text: """A powerful, extensible, and easy-to-use option parser.
  
  By Greg Ward <gward@python.net>
  
  Originally distributed as Optik.
  
  For support, use the optik-users@lists.sourceforge.net mailing list
  (http://lists.sourceforge.net/lists/listinfo/optik-users).
  
  Simple usage example:
  
     from optparse import OptionParser
  
     parser = OptionParser()
     parser.add_option("-f", "--file", dest="filename",
                       help="write report to FILE", metavar="FILE")
     parser.add_option("-q", "--quiet",
                       action="store_false", dest="verbose", default=True,
                       help="don't print status messages to stdout")
  
     (options, args) = parser.parse_args()
  """
  
  __version__ = "1.5.3"
  
  __all__ = ['Option',
             'make_option',
             'SUPPRESS_HELP',
             'SUPPRESS_USAGE',
             'Values',
             'OptionContainer',
             'OptionGroup',
             'OptionParser',
             'HelpFormatter',
             'IndentedHelpFormatter',
             'TitledHelpFormatter',
             'OptParseError',
             'OptionError',
             'OptionConflictError',
             'OptionValueError',
             'BadOptionError',
             'check_choice']
  
  __copyright__ = """
  Copyright (c) 2001-2006 Gregory P. Ward.  All rights reserved.
  Copyright (c) 2002-2006 Python Software Foundation.  All rights reserved.
  
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are
  met:
  
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
  
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
  
    * Neither the name of the author nor the names of its
      contributors may be used to endorse or promote products derived from
      this software without specific prior written permission.
  
  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR
  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  """
  
  import sys
  import os
  import textwrap
  
  
  def _repr(self):
      return "<%s at 0x%x: %s>" % (self.__class__.__name__, id(self), self)
  
  
  # This file was generated from:
  #   Id: option_parser.py 527 2006-07-23 15:21:30Z greg
  #   Id: option.py 522 2006-06-11 16:22:03Z gward
  #   Id: help.py 527 2006-07-23 15:21:30Z greg
  #   Id: errors.py 509 2006-04-20 00:58:24Z gward
  
  try:
      from gettext import gettext, ngettext
  except ImportError:
      def gettext(message):
          return message
  
      def ngettext(singular, plural, n):
          if n == 1:
              return singular
          return plural
  
  _ = gettext
  
  
  class OptParseError (Exception):
      def __init__(self, msg):
          self.msg = msg
  
      def __str__(self):
          return self.msg
  
  
  class OptionError (OptParseError):
      """
      Raised if an Option instance is created with invalid or
      inconsistent arguments.
      """
  
      def __init__(self, msg, option):
          self.msg = msg
          self.option_id = str(option)
  
      def __str__(self):
          if self.option_id:
              return "option %s: %s" % (self.option_id, self.msg)
          else:
              return self.msg
  
  
  class OptionConflictError (OptionError):
      """
      Raised if conflicting options are added to an OptionParser.
      """
  
  
  class OptionValueError (OptParseError):
      """
      Raised if an invalid option value is encountered on the command
      line.
      """
  
  
  class BadOptionError (OptParseError):
      """
      Raised if an invalid option is seen on the command line.
      """
  
      def __init__(self, opt_str):
          self.opt_str = opt_str
  
      def __str__(self):
          return _("no such option: %s") % self.opt_str
  
  
  class AmbiguousOptionError (BadOptionError):
      """
      Raised if an ambiguous option is seen on the command line.
      """
  
      def __init__(self, opt_str, possibilities):
          BadOptionError.__init__(self, opt_str)
          self.possibilities = possibilities
  
      def __str__(self):
          return (_("ambiguous option: %s (%s?)")
                  % (self.opt_str, ", ".join(self.possibilities)))
  
  
  class HelpFormatter:
  
      """
      Abstract base class for formatting option help.  OptionParser
      instances should use one of the HelpFormatter subclasses for
      formatting help; by default IndentedHelpFormatter is used.
  
      Instance attributes:
        parser : OptionParser
          the controlling OptionParser instance
        indent_increment : int
          the number of columns to indent per nesting level
        max_help_position : int
          the maximum starting column for option help text
        help_position : int
          the calculated starting column for option help text;
          initially the same as the maximum
        width : int
          total number of columns for output (pass None to constructor for
          this value to be taken from the $COLUMNS environment variable)
        level : int
          current indentation level
        current_indent : int
          current indentation level (in columns)
        help_width : int
          number of columns available for option help text (calculated)
        default_tag : str
          text to replace with each option's default value, "%default"
          by default.  Set to false value to disable default value expansion.
        option_strings : { Option : str }
          maps Option instances to the snippet of help text explaining
          the syntax of that option, e.g. "-h, --help" or
          "-fFILE, --file=FILE"
        _short_opt_fmt : str
          format string controlling how short options with values are
          printed in help text.  Must be either "%s%s" ("-fFILE") or
          "%s %s" ("-f FILE"), because those are the two syntaxes that
          Optik supports.
        _long_opt_fmt : str
          similar but for long options; must be either "%s %s" ("--file FILE")
          or "%s=%s" ("--file=FILE").
      """
  
      NO_DEFAULT_VALUE = "none"
  
      def __init__(self,
                   indent_increment,
                   max_help_position,
                   width,
                   short_first):
          self.parser = None
          self.indent_increment = indent_increment
          if width is None:
              try:
                  width = int(os.environ['COLUMNS'])
              except (KeyError, ValueError):
                  width = 80
              width -= 2
          self.width = width
          self.help_position = self.max_help_position = \
              min(max_help_position, max(width - 20, indent_increment * 2))
          self.current_indent = 0
          self.level = 0
          self.help_width = None          # computed later
          self.short_first = short_first
          self.default_tag = "%default"
          self.option_strings = {}
          self._short_opt_fmt = "%s %s"
          self._long_opt_fmt = "%s=%s"
  
      def set_parser(self, parser):
          self.parser = parser
  
      def set_short_opt_delimiter(self, delim):
          if delim not in ("", " "):
              raise ValueError(
                  "invalid metavar delimiter for short options: %r" % delim)
          self._short_opt_fmt = "%s" + delim + "%s"
  
      def set_long_opt_delimiter(self, delim):
          if delim not in ("=", " "):
              raise ValueError(
                  "invalid metavar delimiter for long options: %r" % delim)
          self._long_opt_fmt = "%s" + delim + "%s"
  
      def indent(self):
          self.current_indent += self.indent_increment
          self.level += 1
  
      def dedent(self):
          self.current_indent -= self.indent_increment
          assert self.current_indent >= 0, "Indent decreased below 0."
          self.level -= 1
  
      def format_usage(self, usage):
          raise NotImplementedError("subclasses must implement")
  
      def format_heading(self, heading):
          raise NotImplementedError("subclasses must implement")
  
      def _format_text(self, text):
          """
          Format a paragraph of free-form text for inclusion in the
          help output at the current indentation level.
          """
          text_width = max(self.width - self.current_indent, 11)
          indent = " "*self.current_indent
          return textwrap.fill(text,
                               text_width,
                               initial_indent=indent,
                               subsequent_indent=indent)
  
      def format_description(self, description):
          if description:
              return self._format_text(description) + "\n"
          else:
              return ""
  
      def format_epilog(self, epilog):
          if epilog:
              return "\n" + self._format_text(epilog) + "\n"
          else:
              return ""
  
      def expand_default(self, option):
          if self.parser is None or not self.default_tag:
              return option.help
  
          default_value = self.parser.defaults.get(option.dest)
          if default_value is NO_DEFAULT or default_value is None:
              default_value = self.NO_DEFAULT_VALUE
  
          return option.help.replace(self.default_tag, str(default_value))
  
      def format_option(self, option):
          # The help for each option consists of two parts:
          #   * the opt strings and metavars
          #     eg. ("-x", or "-fFILENAME, --file=FILENAME")
          #   * the user-supplied help string
          #     eg. ("turn on expert mode", "read data from FILENAME")
          #
          # If possible, we write both of these on the same line:
          #   -x      turn on expert mode
          #
          # But if the opt string list is too long, we put the help
          # string on a second line, indented to the same column it would
          # start in if it fit on the first line.
          #   -fFILENAME, --file=FILENAME
          #           read data from FILENAME
          result = []
          opts = self.option_strings[option]
          opt_width = self.help_position - self.current_indent - 2
          if len(opts) > opt_width:
              opts = "%*s%s\n" % (self.current_indent, "", opts)
              indent_first = self.help_position
          else:                       # start help on same line as opts
              opts = "%*s%-*s  " % (self.current_indent, "", opt_width, opts)
              indent_first = 0
          result.append(opts)
          if option.help:
              help_text = self.expand_default(option)
              help_lines = textwrap.wrap(help_text, self.help_width)
              result.append("%*s%s\n" % (indent_first, "", help_lines[0]))
              result.extend(["%*s%s\n" % (self.help_position, "", line)
                             for line in help_lines[1:]])
          elif opts[-1] != "\n":
              result.append("\n")
          return "".join(result)
  
      def store_option_strings(self, parser):
          self.indent()
          max_len = 0
          for opt in parser.option_list:
              strings = self.format_option_strings(opt)
              self.option_strings[opt] = strings
              max_len = max(max_len, len(strings) + self.current_indent)
          self.indent()
          for group in parser.option_groups:
              for opt in group.option_list:
                  strings = self.format_option_strings(opt)
                  self.option_strings[opt] = strings
                  max_len = max(max_len, len(strings) + self.current_indent)
          self.dedent()
          self.dedent()
          self.help_position = min(max_len + 2, self.max_help_position)
          self.help_width = max(self.width - self.help_position, 11)
  
      def format_option_strings(self, option):
          """Return a comma-separated list of option strings & metavariables."""
          if option.takes_value():
              metavar = option.metavar or option.dest.upper()
              short_opts = [self._short_opt_fmt % (sopt, metavar)
                            for sopt in option._short_opts]
              long_opts = [self._long_opt_fmt % (lopt, metavar)
                           for lopt in option._long_opts]
          else:
              short_opts = option._short_opts
              long_opts = option._long_opts
  
          if self.short_first:
              opts = short_opts + long_opts
          else:
              opts = long_opts + short_opts
  
          return ", ".join(opts)
  
  
  class IndentedHelpFormatter (HelpFormatter):
      """Format help with indented section bodies.
      """
  
      def __init__(self,
                   indent_increment=2,
                   max_help_position=24,
                   width=None,
                   short_first=1):
          HelpFormatter.__init__(
              self, indent_increment, max_help_position, width, short_first)
  
      def format_usage(self, usage):
          return _("Usage: %s\n") % usage
  
      def format_heading(self, heading):
          return "%*s%s:\n" % (self.current_indent, "", heading)
  
  
  class TitledHelpFormatter (HelpFormatter):
      """Format help with underlined section headers.
      """
  
      def __init__(self,
                   indent_increment=0,
                   max_help_position=24,
                   width=None,
                   short_first=0):
          HelpFormatter.__init__(
              self, indent_increment, max_help_position, width, short_first)
  
      def format_usage(self, usage):
          return "%s  %s\n" % (self.format_heading(_("Usage")), usage)
  
      def format_heading(self, heading):
          return "%s\n%s\n" % (heading, "=-"[self.level] * len(heading))
  
  
  def _parse_num(val, type):
      if val[:2].lower() == "0x":         # hexadecimal
          radix = 16
      elif val[:2].lower() == "0b":       # binary
          radix = 2
          val = val[2:] or "0"            # have to remove "0b" prefix
      elif val[:1] == "0":                # octal
          radix = 8
      else:                               # decimal
          radix = 10
  
      return type(val, radix)
  
  
  def _parse_int(val):
      return _parse_num(val, int)
  
  
  _builtin_cvt = {"int": (_parse_int, _("integer")),
                  "long": (_parse_int, _("integer")),
                  "float": (float, _("floating-point")),
                  "complex": (complex, _("complex"))}
  
  
  def check_builtin(option, opt, value):
      (cvt, what) = _builtin_cvt[option.type]
      try:
          return cvt(value)
      except ValueError:
          raise OptionValueError(
              _("option %s: invalid %s value: %r") % (opt, what, value))
  
  
  def check_choice(option, opt, value):
      if value in option.choices:
          return value
      else:
          choices = ", ".join(map(repr, option.choices))
          raise OptionValueError(
              _("option %s: invalid choice: %r (choose from %s)")
              % (opt, value, choices))
  
  
  # Not supplying a default is different from a default of None,
  # so we need an explicit "not supplied" value.
  NO_DEFAULT = ("NO", "DEFAULT")
  
  
  class Option:
      """
      Instance attributes:
        _short_opts : [string]
        _long_opts : [string]
  
        action : string
        type : string
        dest : string
        default : any
        nargs : int
        const : any
        choices : [string]
        callback : function
        callback_args : (any*)
        callback_kwargs : { string : any }
        help : string
        metavar : string
      """
  
      # The list of instance attributes that may be set through
      # keyword args to the constructor.
      ATTRS = ['action',
               'type',
               'dest',
               'default',
               'nargs',
               'const',
               'choices',
               'callback',
               'callback_args',
               'callback_kwargs',
               'help',
               'metavar']
  
      # The set of actions allowed by option parsers.  Explicitly listed
      # here so the constructor can validate its arguments.
      ACTIONS = ("store",
                 "store_const",
                 "store_true",
                 "store_false",
                 "append",
                 "append_const",
                 "count",
                 "callback",
                 "help",
                 "version")
  
      # The set of actions that involve storing a value somewhere;
      # also listed just for constructor argument validation.  (If
      # the action is one of these, there must be a destination.)
      STORE_ACTIONS = ("store",
                       "store_const",
                       "store_true",
                       "store_false",
                       "append",
                       "append_const",
                       "count")
  
      # The set of actions for which it makes sense to supply a value
      # type, ie. which may consume an argument from the command line.
      TYPED_ACTIONS = ("store",
                       "append",
                       "callback")
  
      # The set of actions which *require* a value type, ie. that
      # always consume an argument from the command line.
      ALWAYS_TYPED_ACTIONS = ("store",
                              "append")
  
      # The set of actions which take a 'const' attribute.
      CONST_ACTIONS = ("store_const",
                       "append_const")
  
      # The set of known types for option parsers.  Again, listed here for
      # constructor argument validation.
      TYPES = ("string", "int", "long", "float", "complex", "choice")
  
      # Dictionary of argument checking functions, which convert and
      # validate option arguments according to the option type.
      #
      # Signature of checking functions is:
      #   check(option : Option, opt : string, value : string) -> any
      # where
      #   option is the Option instance calling the checker
      #   opt is the actual option seen on the command-line
      #     (eg. "-a", "--file")
      #   value is the option argument seen on the command-line
      #
      # The return value should be in the appropriate Python type
      # for option.type -- eg. an integer if option.type == "int".
      #
      # If no checker is defined for a type, arguments will be
      # unchecked and remain strings.
      TYPE_CHECKER = {"int": check_builtin,
                      "long": check_builtin,
                      "float": check_builtin,
                      "complex": check_builtin,
                      "choice": check_choice,
                      }
  
      # CHECK_METHODS is a list of unbound method objects; they are called
      # by the constructor, in order, after all attributes are
      # initialized.  The list is created and filled in later, after all
      # the methods are actually defined.  (I just put it here because I
      # like to define and document all class attributes in the same
      # place.)  Subclasses that add another _check_*() method should
      # define their own CHECK_METHODS list that adds their check method
      # to those from this class.
      CHECK_METHODS = None
  
      # -- Constructor/initialization methods ----------------------------
  
      def __init__(self, *opts, **attrs):
          # Set _short_opts, _long_opts attrs from 'opts' tuple.
          # Have to be set now, in case no option strings are supplied.
          self._short_opts = []
          self._long_opts = []
          opts = self._check_opt_strings(opts)
          self._set_opt_strings(opts)
  
          # Set all other attrs (action, type, etc.) from 'attrs' dict
          self._set_attrs(attrs)
  
          # Check all the attributes we just set.  There are lots of
          # complicated interdependencies, but luckily they can be farmed
          # out to the _check_*() methods listed in CHECK_METHODS -- which
          # could be handy for subclasses!  The one thing these all share
          # is that they raise OptionError if they discover a problem.
          for checker in self.CHECK_METHODS:
              checker(self)
  
      def _check_opt_strings(self, opts):
          # Filter out None because early versions of Optik had exactly
          # one short option and one long option, either of which
          # could be None.
          opts = [opt for opt in opts if opt]
          if not opts:
              raise TypeError("at least one option string must be supplied")
          return opts
  
      def _set_opt_strings(self, opts):
          for opt in opts:
              if len(opt) < 2:
                  raise OptionError(
                      "invalid option string %r: "
                      "must be at least two characters long" % opt, self)
              elif len(opt) == 2:
                  if not (opt[0] == "-" and opt[1] != "-"):
                      raise OptionError(
                          "invalid short option string %r: "
                          "must be of the form -x, (x any non-dash char)" % opt,
                          self)
                  self._short_opts.append(opt)
              else:
                  if not (opt[0:2] == "--" and opt[2] != "-"):
                      raise OptionError(
                          "invalid long option string %r: "
                          "must start with --, followed by non-dash" % opt,
                          self)
                  self._long_opts.append(opt)
  
      def _set_attrs(self, attrs):
          for attr in self.ATTRS:
              if attr in attrs:
                  setattr(self, attr, attrs[attr])
                  del attrs[attr]
              else:
                  if attr == 'default':
                      setattr(self, attr, NO_DEFAULT)
                  else:
                      setattr(self, attr, None)
          if attrs:
              attrs = sorted(attrs.keys())
              raise OptionError(
                  "invalid keyword arguments: %s" % ", ".join(attrs),
                  self)
  
      # -- Constructor validation methods --------------------------------
  
      def _check_action(self):
          if self.action is None:
              self.action = "store"
          elif self.action not in self.ACTIONS:
              raise OptionError("invalid action: %r" % self.action, self)
  
      def _check_type(self):
          if self.type is None:
              if self.action in self.ALWAYS_TYPED_ACTIONS:
                  if self.choices is not None:
                      # The "choices" attribute implies "choice" type.
                      self.type = "choice"
                  else:
                      # No type given?  "string" is the most sensible default.
                      self.type = "string"
          else:
              # Allow type objects or builtin type conversion functions
              # (int, str, etc.) as an alternative to their names.
              if isinstance(self.type, type):
                  self.type = self.type.__name__
  
              if self.type == "str":
                  self.type = "string"
  
              if self.type not in self.TYPES:
                  raise OptionError("invalid option type: %r" % self.type, self)
              if self.action not in self.TYPED_ACTIONS:
                  raise OptionError(
                      "must not supply a type for action %r" % self.action, self)
  
      def _check_choice(self):
          if self.type == "choice":
              if self.choices is None:
                  raise OptionError(
                      "must supply a list of choices for type 'choice'", self)
              elif not isinstance(self.choices, (tuple, list)):
                  raise OptionError(
                      "choices must be a list of strings ('%s' supplied)"
                      % str(type(self.choices)).split("'")[1], self)
          elif self.choices is not None:
              raise OptionError(
                  "must not supply choices for type %r" % self.type, self)
  
      def _check_dest(self):
          # No destination given, and we need one for this action.  The
          # self.type check is for callbacks that take a value.
          takes_value = (self.action in self.STORE_ACTIONS or
                         self.type is not None)
          if self.dest is None and takes_value:
  
              # Glean a destination from the first long option string,
              # or from the first short option string if no long options.
              if self._long_opts:
                  # eg. "--foo-bar" -> "foo_bar"
                  self.dest = self._long_opts[0][2:].replace('-', '_')
              else:
                  self.dest = self._short_opts[0][1]
  
      def _check_const(self):
          if self.action not in self.CONST_ACTIONS and self.const is not None:
              raise OptionError(
                  "'const' must not be supplied for action %r" % self.action,
                  self)
  
      def _check_nargs(self):
          if self.action in self.TYPED_ACTIONS:
              if self.nargs is None:
                  self.nargs = 1
          elif self.nargs is not None:
              raise OptionError(
                  "'nargs' must not be supplied for action %r" % self.action,
                  self)
  
      def _check_callback(self):
          if self.action == "callback":
              if not callable(self.callback):
                  raise OptionError(
                      "callback not callable: %r" % self.callback, self)
              if (self.callback_args is not None and
                      not isinstance(self.callback_args, tuple)):
                  raise OptionError(
                      "callback_args, if supplied, must be a tuple: not %r"
                      % self.callback_args, self)
              if (self.callback_kwargs is not None and
                      not isinstance(self.callback_kwargs, dict)):
                  raise OptionError(
                      "callback_kwargs, if supplied, must be a dict: not %r"
                      % self.callback_kwargs, self)
          else:
              if self.callback is not None:
                  raise OptionError(
                      "callback supplied (%r) for non-callback option"
                      % self.callback, self)
              if self.callback_args is not None:
                  raise OptionError(
                      "callback_args supplied for non-callback option", self)
              if self.callback_kwargs is not None:
                  raise OptionError(
                      "callback_kwargs supplied for non-callback option", self)
  
      CHECK_METHODS = [_check_action,
                       _check_type,
                       _check_choice,
                       _check_dest,
                       _check_const,
                       _check_nargs,
                       _check_callback]
  
      # -- Miscellaneous methods -----------------------------------------
  
      def __str__(self):
          return "/".join(self._short_opts + self._long_opts)
  
      __repr__ = _repr
  
      def takes_value(self):
          return self.type is not None
  
      def get_opt_string(self):
          if self._long_opts:
              return self._long_opts[0]
          else:
              return self._short_opts[0]
  
      # -- Processing methods --------------------------------------------
  
      def check_value(self, opt, value):
          checker = self.TYPE_CHECKER.get(self.type)
          if checker is None:
              return value
          else:
              return checker(self, opt, value)
  
      def convert_value(self, opt, value):
          if value is not None:
              if self.nargs == 1:
                  return self.check_value(opt, value)
              else:
                  return tuple([self.check_value(opt, v) for v in value])
  
      def process(self, opt, value, values, parser):
  
          # First, convert the value(s) to the right type.  Howl if any
          # value(s) are bogus.
          value = self.convert_value(opt, value)
  
          # And then take whatever action is expected of us.
          # This is a separate method to make life easier for
          # subclasses to add new actions.
          return self.take_action(
              self.action, self.dest, opt, value, values, parser)
  
      def take_action(self, action, dest, opt, value, values, parser):
          if action == "store":
              setattr(values, dest, value)
          elif action == "store_const":
              setattr(values, dest, self.const)
          elif action == "store_true":
              setattr(values, dest, True)
          elif action == "store_false":
              setattr(values, dest, False)
          elif action == "append":
              values.ensure_value(dest, []).append(value)
          elif action == "append_const":
              values.ensure_value(dest, []).append(self.const)
          elif action == "count":
              setattr(values, dest, values.ensure_value(dest, 0) + 1)
          elif action == "callback":
              args = self.callback_args or ()
              kwargs = self.callback_kwargs or {}
              self.callback(self, opt, value, parser, *args, **kwargs)
          elif action == "help":
              parser.print_help()
              parser.exit()
          elif action == "version":
              parser.print_version()
              parser.exit()
          else:
              raise ValueError("unknown action %r" % self.action)
  
          return 1
  
  # class Option
  
  
  SUPPRESS_HELP = "SUPPRESS"+"HELP"
  SUPPRESS_USAGE = "SUPPRESS"+"USAGE"
  
  
  class Values:
  
      def __init__(self, defaults=None):
          if defaults:
              for (attr, val) in defaults.items():
                  setattr(self, attr, val)
  
      def __str__(self):
          return str(self.__dict__)
  
      __repr__ = _repr
  
      def __eq__(self, other):
          if isinstance(other, Values):
              return self.__dict__ == other.__dict__
          elif isinstance(other, dict):
              return self.__dict__ == other
          else:
              return NotImplemented
  
      def _update_careful(self, dict):
          """
          Update the option values from an arbitrary dictionary, but only
          use keys from dict that already have a corresponding attribute
          in self.  Any keys in dict without a corresponding attribute
          are silently ignored.
          """
          for attr in dir(self):
              if attr in dict:
                  dval = dict[attr]
                  if dval is not None:
                      setattr(self, attr, dval)
  
      def _update_loose(self, dict):
          """
          Update the option values from an arbitrary dictionary,
          using all keys from the dictionary regardless of whether
          they have a corresponding attribute in self or not.
          """
          self.__dict__.update(dict)
  
      def _update(self, dict, mode):
          if mode == "careful":
              self._update_careful(dict)
          elif mode == "loose":
              self._update_loose(dict)
          else:
              raise ValueError("invalid update mode: %r" % mode)
  
      def read_module(self, modname, mode="careful"):
          __import__(modname)
          mod = sys.modules[modname]
          self._update(vars(mod), mode)
  
      def read_file(self, filename, mode="careful"):
          vars = {}
          exec(open(filename).read(), vars)
          self._update(vars, mode)
  
      def ensure_value(self, attr, value):
          if not hasattr(self, attr) or getattr(self, attr) is None:
              setattr(self, attr, value)
          return getattr(self, attr)
  
  
  class OptionContainer:
  
      """
      Abstract base class.
  
      Class attributes:
        standard_option_list : [Option]
          list of standard options that will be accepted by all instances
          of this parser class (intended to be overridden by subclasses).
  
      Instance attributes:
        option_list : [Option]
          the list of Option objects contained by this OptionContainer
        _short_opt : { string : Option }
          dictionary mapping short option strings, eg. "-f" or "-X",
          to the Option instances that implement them.  If an Option
          has multiple short option strings, it will appear in this
          dictionary multiple times. [1]
        _long_opt : { string : Option }
          dictionary mapping long option strings, eg. "--file" or
          "--exclude", to the Option instances that implement them.
          Again, a given Option can occur multiple times in this
          dictionary. [1]
        defaults : { string : any }
          dictionary mapping option destination names to default
          values for each destination [1]
  
      [1] These mappings are common to (shared by) all components of the
          controlling OptionParser, where they are initially created.
  
      """
  
      def __init__(self, option_class, conflict_handler, description):
          # Initialize the option list and related data structures.
          # This method must be provided by subclasses, and it must
          # initialize at least the following instance attributes:
          # option_list, _short_opt, _long_opt, defaults.
          self._create_option_list()
  
          self.option_class = option_class
          self.set_conflict_handler(conflict_handler)
          self.set_description(description)
  
      def _create_option_mappings(self):
          # For use by OptionParser constructor -- create the main
          # option mappings used by this OptionParser and all
          # OptionGroups that it owns.
          self._short_opt = {}            # single letter -> Option instance
          self._long_opt = {}             # long option -> Option instance
          self.defaults = {}              # maps option dest -> default value
  
      def _share_option_mappings(self, parser):
          # For use by OptionGroup constructor -- use shared option
          # mappings from the OptionParser that owns this OptionGroup.
          self._short_opt = parser._short_opt
          self._long_opt = parser._long_opt
          self.defaults = parser.defaults
  
      def set_conflict_handler(self, handler):
          if handler not in ("error", "resolve"):
              raise ValueError("invalid conflict_resolution value %r" % handler)
          self.conflict_handler = handler
  
      def set_description(self, description):
          self.description = description
  
      def get_description(self):
          return self.description
  
      def destroy(self):
          """see OptionParser.destroy()."""
          del self._short_opt
          del self._long_opt
          del self.defaults
  
      # -- Option-adding methods -----------------------------------------
  
      def _check_conflict(self, option):
          conflict_opts = []
          for opt in option._short_opts:
              if opt in self._short_opt:
                  conflict_opts.append((opt, self._short_opt[opt]))
          for opt in option._long_opts:
              if opt in self._long_opt:
                  conflict_opts.append((opt, self._long_opt[opt]))
  
          if conflict_opts:
              handler = self.conflict_handler
              if handler == "error":
                  raise OptionConflictError(
                      "conflicting option string(s): %s"
                      % ", ".join([co[0] for co in conflict_opts]),
                      option)
              elif handler == "resolve":
                  for (opt, c_option) in conflict_opts:
                      if opt.startswith("--"):
                          c_option._long_opts.remove(opt)
                          del self._long_opt[opt]
                      else:
                          c_option._short_opts.remove(opt)
                          del self._short_opt[opt]
                      if not (c_option._short_opts or c_option._long_opts):
                          c_option.container.option_list.remove(c_option)
  
      def add_option(self, *args, **kwargs):
          """add_option(Option)
             add_option(opt_str, ..., kwarg=val, ...)
          """
          if isinstance(args[0], str):
              option = self.option_class(*args, **kwargs)
          elif len(args) == 1 and not kwargs:
              option = args[0]
              if not isinstance(option, Option):
                  raise TypeError("not an Option instance: %r" % option)
          else:
              raise TypeError("invalid arguments")
  
          self._check_conflict(option)
  
          self.option_list.append(option)
          option.container = self
          for opt in option._short_opts:
              self._short_opt[opt] = option
          for opt in option._long_opts:
              self._long_opt[opt] = option
  
          if option.dest is not None:     # option has a dest, we need a default
              if option.default is not NO_DEFAULT:
                  self.defaults[option.dest] = option.default
              elif option.dest not in self.defaults:
                  self.defaults[option.dest] = None
  
          return option
  
      def add_options(self, option_list):
          for option in option_list:
              self.add_option(option)
  
      # -- Option query/removal methods ----------------------------------
  
      def get_option(self, opt_str):
          return (self._short_opt.get(opt_str) or
                  self._long_opt.get(opt_str))
  
      def has_option(self, opt_str):
          return (opt_str in self._short_opt or
                  opt_str in self._long_opt)
  
      def remove_option(self, opt_str):
          option = self._short_opt.get(opt_str)
          if option is None:
              option = self._long_opt.get(opt_str)
          if option is None:
              raise ValueError("no such option %r" % opt_str)
  
          for opt in option._short_opts:
              del self._short_opt[opt]
          for opt in option._long_opts:
              del self._long_opt[opt]
          option.container.option_list.remove(option)
  
      # -- Help-formatting methods ---------------------------------------
  
      def format_option_help(self, formatter):
          if not self.option_list:
              return ""
          result = []
          for option in self.option_list:
              if not option.help is SUPPRESS_HELP:
                  result.append(formatter.format_option(option))
          return "".join(result)
  
      def format_description(self, formatter):
          return formatter.format_description(self.get_description())
  
      def format_help(self, formatter):
          result = []
          if self.description:
              result.append(self.format_description(formatter))
          if self.option_list:
              result.append(self.format_option_help(formatter))
          return "\n".join(result)
  
  
  class OptionGroup (OptionContainer):
  
      def __init__(self, parser, title, description=None):
          self.parser = parser
          OptionContainer.__init__(
              self, parser.option_class, parser.conflict_handler, description)
          self.title = title
  
      def _create_option_list(self):
          self.option_list = []
          self._share_option_mappings(self.parser)
  
      def set_title(self, title):
          self.title = title
  
      def destroy(self):
          """see OptionParser.destroy()."""
          OptionContainer.destroy(self)
          del self.option_list
  
      # -- Help-formatting methods ---------------------------------------
  
      def format_help(self, formatter):
          result = formatter.format_heading(self.title)
          formatter.indent()
          result += OptionContainer.format_help(self, formatter)
          formatter.dedent()
          return result
  
  
  class OptionParser (OptionContainer):
  
      """
      Class attributes:
        standard_option_list : [Option]
          list of standard options that will be accepted by all instances
          of this parser class (intended to be overridden by subclasses).
  
      Instance attributes:
        usage : string
          a usage string for your program.  Before it is displayed
          to the user, "%prog" will be expanded to the name of
          your program (self.prog or os.path.basename(sys.argv[0])).
        prog : string
          the name of the current program (to override
          os.path.basename(sys.argv[0])).
        description : string
          A paragraph of text giving a brief overview of your program.
          optparse reformats this paragraph to fit the current terminal
          width and prints it when the user requests help (after usage,
          but before the list of options).
        epilog : string
          paragraph of help text to print after option help
  
        option_groups : [OptionGroup]
          list of option groups in this parser (option groups are
          irrelevant for parsing the command-line, but very useful
          for generating help)
  
        allow_interspersed_args : bool = true
          if true, positional arguments may be interspersed with options.
          Assuming -a and -b each take a single argument, the command-line
            -ablah foo bar -bboo baz
          will be interpreted the same as
            -ablah -bboo -- foo bar baz
          If this flag were false, that command line would be interpreted as
            -ablah -- foo bar -bboo baz
          -- ie. we stop processing options as soon as we see the first
          non-option argument.  (This is the tradition followed by
          Python's getopt module, Perl's Getopt::Std, and other argument-
          parsing libraries, but it is generally annoying to users.)
  
        process_default_values : bool = true
          if true, option default values are processed similarly to option
          values from the command line: that is, they are passed to the
          type-checking function for the option's type (as long as the
          default value is a string).  (This really only matters if you
          have defined custom types; see SF bug #955889.)  Set it to false
          to restore the behaviour of Optik 1.4.1 and earlier.
  
        rargs : [string]
          the argument list currently being parsed.  Only set when
          parse_args() is active, and continually trimmed down as
          we consume arguments.  Mainly there for the benefit of
          callback options.
        largs : [string]
          the list of leftover arguments that we have skipped while
          parsing options.  If allow_interspersed_args is false, this
          list is always empty.
        values : Values
          the set of option values currently being accumulated.  Only
          set when parse_args() is active.  Also mainly for callbacks.
  
      Because of the 'rargs', 'largs', and 'values' attributes,
      OptionParser is not thread-safe.  If, for some perverse reason, you
      need to parse command-line arguments simultaneously in different
      threads, use different OptionParser instances.
  
      """
  
      standard_option_list = []
  
      def __init__(self,
                   usage=None,
                   option_list=None,
                   option_class=Option,
                   version=None,
                   conflict_handler="error",
                   description=None,
                   formatter=None,
                   add_help_option=True,
                   prog=None,
                   epilog=None):
          OptionContainer.__init__(
              self, option_class, conflict_handler, description)
          self.set_usage(usage)
          self.prog = prog
          self.version = version
          self.allow_interspersed_args = True
          self.process_default_values = True
          if formatter is None:
              formatter = IndentedHelpFormatter()
          self.formatter = formatter
          self.formatter.set_parser(self)
          self.epilog = epilog
  
          # Populate the option list; initial sources are the
          # standard_option_list class attribute, the 'option_list'
          # argument, and (if applicable) the _add_version_option() and
          # _add_help_option() methods.
          self._populate_option_list(option_list,
                                     add_help=add_help_option)
  
          self._init_parsing_state()
  
      def destroy(self):
          """
          Declare that you are done with this OptionParser.  This cleans up
          reference cycles so the OptionParser (and all objects referenced by
          it) can be garbage-collected promptly.  After calling destroy(), the
          OptionParser is unusable.
          """
          OptionContainer.destroy(self)
          for group in self.option_groups:
              group.destroy()
          del self.option_list
          del self.option_groups
          del self.formatter
  
      # -- Private methods -----------------------------------------------
      # (used by our or OptionContainer's constructor)
  
      def _create_option_list(self):
          self.option_list = []
          self.option_groups = []
          self._create_option_mappings()
  
      def _add_help_option(self):
          self.add_option("-h", "--help",
                          action="help",
                          help=_("show this help message and exit"))
  
      def _add_version_option(self):
          self.add_option("--version",
                          action="version",
                          help=_("show program's version number and exit"))
  
      def _populate_option_list(self, option_list, add_help=True):
          if self.standard_option_list:
              self.add_options(self.standard_option_list)
          if option_list:
              self.add_options(option_list)
          if self.version:
              self._add_version_option()
          if add_help:
              self._add_help_option()
  
      def _init_parsing_state(self):
          # These are set in parse_args() for the convenience of callbacks.
          self.rargs = None
          self.largs = None
          self.values = None
  
      # -- Simple modifier methods ---------------------------------------
  
      def set_usage(self, usage):
          if usage is None:
              self.usage = _("%prog [options]")
          elif usage is SUPPRESS_USAGE:
              self.usage = None
          # For backwards compatibility with Optik 1.3 and earlier.
          elif usage.lower().startswith("usage: "):
              self.usage = usage[7:]
          else:
              self.usage = usage
  
      def enable_interspersed_args(self):
          """Set parsing to not stop on the first non-option, allowing
          interspersing switches with command arguments. This is the
          default behavior. See also disable_interspersed_args() and the
          class documentation description of the attribute
          allow_interspersed_args."""
          self.allow_interspersed_args = True
  
      def disable_interspersed_args(self):
          """Set parsing to stop on the first non-option. Use this if
          you have a command processor which runs another command that
          has options of its own and you want to make sure these options
          don't get confused.
          """
          self.allow_interspersed_args = False
  
      def set_process_default_values(self, process):
          self.process_default_values = process
  
      def set_default(self, dest, value):
          self.defaults[dest] = value
  
      def set_defaults(self, **kwargs):
          self.defaults.update(kwargs)
  
      def _get_all_options(self):
          options = self.option_list[:]
          for group in self.option_groups:
              options.extend(group.option_list)
          return options
  
      def get_default_values(self):
          if not self.process_default_values:
              # Old, pre-Optik 1.5 behaviour.
              return Values(self.defaults)
  
          defaults = self.defaults.copy()
          for option in self._get_all_options():
              default = defaults.get(option.dest)
              if isinstance(default, str):
                  opt_str = option.get_opt_string()
                  defaults[option.dest] = option.check_value(opt_str, default)
  
          return Values(defaults)
  
      # -- OptionGroup methods -------------------------------------------
  
      def add_option_group(self, *args, **kwargs):
          # XXX lots of overlap with OptionContainer.add_option()
          if isinstance(args[0], str):
              group = OptionGroup(self, *args, **kwargs)
          elif len(args) == 1 and not kwargs:
              group = args[0]
              if not isinstance(group, OptionGroup):
                  raise TypeError("not an OptionGroup instance: %r" % group)
              if group.parser is not self:
                  raise ValueError("invalid OptionGroup (wrong parser)")
          else:
              raise TypeError("invalid arguments")
  
          self.option_groups.append(group)
          return group
  
      def get_option_group(self, opt_str):
          option = (self._short_opt.get(opt_str) or
                    self._long_opt.get(opt_str))
          if option and option.container is not self:
              return option.container
          return None
  
      # -- Option-parsing methods ----------------------------------------
  
      def _get_args(self, args):
          if args is None:
              return sys.argv[1:]
          else:
              return args[:]              # don't modify caller's list
  
      def parse_args(self, args=None, values=None):
          """
          parse_args(args : [string] = sys.argv[1:],
                     values : Values = None)
          -> (values : Values, args : [string])
  
          Parse the command-line options found in 'args' (default:
          sys.argv[1:]).  Any errors result in a call to 'error()', which
          by default prints the usage message to stderr and calls
          sys.exit() with an error message.  On success returns a pair
          (values, args) where 'values' is a Values instance (with all
          your option values) and 'args' is the list of arguments left
          over after parsing options.
          """
          rargs = self._get_args(args)
          if values is None:
              values = self.get_default_values()
  
          # Store the halves of the argument list as attributes for the
          # convenience of callbacks:
          #   rargs
          #     the rest of the command-line (the "r" stands for
          #     "remaining" or "right-hand")
          #   largs
          #     the leftover arguments -- ie. what's left after removing
          #     options and their arguments (the "l" stands for "leftover"
          #     or "left-hand")
          self.rargs = rargs
          self.largs = largs = []
          self.values = values
  
          try:
              stop = self._process_args(largs, rargs, values)
          except (BadOptionError, OptionValueError) as err:
              self.error(str(err))
  
          args = largs + rargs
          return self.check_values(values, args)
  
      def check_values(self, values, args):
          """
          check_values(values : Values, args : [string])
          -> (values : Values, args : [string])
  
          Check that the supplied option values and leftover arguments are
          valid.  Returns the option values and leftover arguments
          (possibly adjusted, possibly completely new -- whatever you
          like).  Default implementation just returns the passed-in
          values; subclasses may override as desired.
          """
          return (values, args)
  
      def _process_args(self, largs, rargs, values):
          """_process_args(largs : [string],
                           rargs : [string],
                           values : Values)
  
          Process command-line arguments and populate 'values', consuming
          options and arguments from 'rargs'.  If 'allow_interspersed_args' is
          false, stop at the first non-option argument.  If true, accumulate any
          interspersed non-option arguments in 'largs'.
          """
          while rargs:
              arg = rargs[0]
              # We handle bare "--" explicitly, and bare "-" is handled by the
              # standard arg handler since the short arg case ensures that the
              # len of the opt string is greater than 1.
              if arg == "--":
                  del rargs[0]
                  return
              elif arg[0:2] == "--":
                  # process a single long option (possibly with value(s))
                  self._process_long_opt(rargs, values)
              elif arg[:1] == "-" and len(arg) > 1:
                  # process a cluster of short options (possibly with
                  # value(s) for the last one only)
                  self._process_short_opts(rargs, values)
              elif self.allow_interspersed_args:
                  largs.append(arg)
                  del rargs[0]
              else:
                  return                  # stop now, leave this arg in rargs
  
          # Say this is the original argument list:
          # [arg0, arg1, ..., arg(i-1), arg(i), arg(i+1), ..., arg(N-1)]
          #                            ^
          # (we are about to process arg(i)).
          #
          # Then rargs is [arg(i), ..., arg(N-1)] and largs is a *subset* of
          # [arg0, ..., arg(i-1)] (any options and their arguments will have
          # been removed from largs).
          #
          # The while loop will usually consume 1 or more arguments per pass.
          # If it consumes 1 (eg. arg is an option that takes no arguments),
          # then after _process_arg() is done the situation is:
          #
          #   largs = subset of [arg0, ..., arg(i)]
          #   rargs = [arg(i+1), ..., arg(N-1)]
          #
          # If allow_interspersed_args is false, largs will always be
          # *empty* -- still a subset of [arg0, ..., arg(i-1)], but
          # not a very interesting subset!
  
      def _match_long_opt(self, opt):
          """_match_long_opt(opt : string) -> string
  
          Determine which long option string 'opt' matches, ie. which one
          it is an unambiguous abbreviation for.  Raises BadOptionError if
          'opt' doesn't unambiguously match any long option string.
          """
          return _match_abbrev(opt, self._long_opt)
  
      def _process_long_opt(self, rargs, values):
          arg = rargs.pop(0)
  
          # Value explicitly attached to arg?  Pretend it's the next
          # argument.
          if "=" in arg:
              (opt, next_arg) = arg.split("=", 1)
              rargs.insert(0, next_arg)
              had_explicit_value = True
          else:
              opt = arg
              had_explicit_value = False
  
          opt = self._match_long_opt(opt)
          option = self._long_opt[opt]
          if option.takes_value():
              nargs = option.nargs
              if len(rargs) < nargs:
                  self.error(ngettext(
                      "%(option)s option requires %(number)d argument",
                      "%(option)s option requires %(number)d arguments",
                      nargs) % {"option": opt, "number": nargs})
              elif nargs == 1:
                  value = rargs.pop(0)
              else:
                  value = tuple(rargs[0:nargs])
                  del rargs[0:nargs]
  
          elif had_explicit_value:
              self.error(_("%s option does not take a value") % opt)
  
          else:
              value = None
  
          option.process(opt, value, values, self)
  
      def _process_short_opts(self, rargs, values):
          arg = rargs.pop(0)
          stop = False
          i = 1
          for ch in arg[1:]:
              opt = "-" + ch
              option = self._short_opt.get(opt)
              i += 1                      # we have consumed a character
  
              if not option:
                  raise BadOptionError(opt)
              if option.takes_value():
                  # Any characters left in arg?  Pretend they're the
                  # next arg, and stop consuming characters of arg.
                  if i < len(arg):
                      rargs.insert(0, arg[i:])
                      stop = True
  
                  nargs = option.nargs
                  if len(rargs) < nargs:
                      self.error(ngettext(
                          "%(option)s option requires %(number)d argument",
                          "%(option)s option requires %(number)d arguments",
                          nargs) % {"option": opt, "number": nargs})
                  elif nargs == 1:
                      value = rargs.pop(0)
                  else:
                      value = tuple(rargs[0:nargs])
                      del rargs[0:nargs]
  
              else:                       # option doesn't take a value
                  value = None
  
              option.process(opt, value, values, self)
  
              if stop:
                  break
  
      # -- Feedback methods ----------------------------------------------
  
      def get_prog_name(self):
          if self.prog is None:
              return os.path.basename(sys.argv[0])
          else:
              return self.prog
  
      def expand_prog_name(self, s):
          return s.replace("%prog", self.get_prog_name())
  
      def get_description(self):
          return self.expand_prog_name(self.description)
  
      def exit(self, status=0, msg=None):
          if msg:
              sys.stderr.write(msg)
          sys.exit(status)
  
      def error(self, msg):
          """error(msg : string)
  
          Print a usage message incorporating 'msg' to stderr and exit.
          If you override this in a subclass, it should not return -- it
          should either exit or raise an exception.
          """
          self.print_usage(sys.stderr)
          self.exit(2, "%s: error: %s\n" % (self.get_prog_name(), msg))
  
      def get_usage(self):
          if self.usage:
              return self.formatter.format_usage(
                  self.expand_prog_name(self.usage))
          else:
              return ""
  
      def print_usage(self, file=None):
          """print_usage(file : file = stdout)
  
          Print the usage message for the current program (self.usage) to
          'file' (default stdout).  Any occurrence of the string "%prog" in
          self.usage is replaced with the name of the current program
          (basename of sys.argv[0]).  Does nothing if self.usage is empty
          or not defined.
          """
          if self.usage:
              print(self.get_usage(), file=file)
  
      def get_version(self):
          if self.version:
              return self.expand_prog_name(self.version)
          else:
              return ""
  
      def print_version(self, file=None):
          """print_version(file : file = stdout)
  
          Print the version message for this program (self.version) to
          'file' (default stdout).  As with print_usage(), any occurrence
          of "%prog" in self.version is replaced by the current program's
          name.  Does nothing if self.version is empty or undefined.
          """
          if self.version:
              print(self.get_version(), file=file)
  
      def format_option_help(self, formatter=None):
          if formatter is None:
              formatter = self.formatter
          formatter.store_option_strings(self)
          result = []
          result.append(formatter.format_heading(_("Options")))
          formatter.indent()
          if self.option_list:
              result.append(OptionContainer.format_option_help(self, formatter))
              result.append("\n")
          for group in self.option_groups:
              result.append(group.format_help(formatter))
              result.append("\n")
          formatter.dedent()
          # Drop the last "\n", or the header if no options or option groups:
          return "".join(result[:-1])
  
      def format_epilog(self, formatter):
          return formatter.format_epilog(self.epilog)
  
      def format_help(self, formatter=None):
          if formatter is None:
              formatter = self.formatter
          result = []
          if self.usage:
              result.append(self.get_usage() + "\n")
          if self.description:
              result.append(self.format_description(formatter) + "\n")
          result.append(self.format_option_help(formatter))
          result.append(self.format_epilog(formatter))
          return "".join(result)
  
      def print_help(self, file=None):
          """print_help(file : file = stdout)
  
          Print an extended help message, listing all options and any
          help text provided with them, to 'file' (default stdout).
          """
          if file is None:
              file = sys.stdout
          file.write(self.format_help())
  
  # class OptionParser
  
  
  def _match_abbrev(s, wordmap):
      """_match_abbrev(s : string, wordmap : {string : Option}) -> string
  
      Return the string key in 'wordmap' for which 's' is an unambiguous
      abbreviation.  If 's' is found to be ambiguous or doesn't match any of
      'words', raise BadOptionError.
      """
      # Is there an exact match?
      if s in wordmap:
          return s
      else:
          # Isolate all words with s as a prefix.
          possibilities = [word for word in wordmap.keys()
                           if word.startswith(s)]
          # No exact match, so there had better be just one possibility.
          if len(possibilities) == 1:
              return possibilities[0]
          elif not possibilities:
              raise BadOptionError(s)
          else:
              # More than one possible completion: ambiguous prefix.
              possibilities.sort()
              raise AmbiguousOptionError(s, possibilities)
  
  
  # Some day, there might be many Option classes.  As of Optik 1.3, the
  # preferred way to instantiate Options is indirectly, via make_option(),
  # which will become a factory function when there are many Option
  # classes.
  make_option = Option
  