class_docstr: class that mimics the necessary behaviour of optparse.Option
  
  it's currently a least effort implementation
  and ignoring choices and integer prefixes
  https://docs.python.org/3/library/optparse.html#optparse-standard-option-types
code: def attrs(self):
      # update any attributes set by processopt
      attrs = "default dest help".split()
      if self.dest:
          attrs.append(self.dest)
      for attr in attrs:
          try:
              self._attrs[attr] = getattr(self, attr)
          except AttributeError:
              pass
      if self._attrs.get("help"):
          a = self._attrs["help"]
          a = a.replace("%default", "%(default)s")
          # a = a.replace('%prog', '%(prog)s')
          self._attrs["help"] = a
      return self._attrs
  
imports: import argparse
  import warnings
  import py
  import six
  from _pytest.config.exceptions import UsageError
label_desc: Use image node_id 3 for calling the Argument obj's underlying member method code with example usage: obj.attrs() and returns: self