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
docstr: directly from optparse
  
  might not be necessary as this is passed to argparse later on
docstr_tok: ["directly","from","optparse","might","not","be","necessary","as","this","is","passed","to","argparse","later","on"]
code: def _set_opt_strings(self, opts):
      """directly from optparse
  
      might not be necessary as this is passed to argparse later on"""
      for opt in opts:
          if len(opt) < 2:
              raise ArgumentError(
                  "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 ArgumentError(
                      "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 ArgumentError(
                      "invalid long option string %r: "
                      "must start with --, followed by non-dash" % opt,
                      self,
                  )
              self._long_opts.append(opt)
  
imports: import argparse
  import warnings
  import py
  import six
  from _pytest.config.exceptions import UsageError
label_desc: Use image node_id 4 for calling the Argument obj's underlying member method code with example usage: obj._set_opt_strings(opts) without return types