class_docstr: A Signature object represents the overall signature of a function.
  It stores a Parameter object for each parameter accepted by the
  function, as well as information specific to the function itself.
  
  A Signature object has the following public attributes and methods:
  
  * parameters : OrderedDict
      An ordered mapping of parameters' names to the corresponding
      Parameter objects (keyword-only arguments are in the same order
      as listed in `code.co_varnames`).
  * return_annotation : object
      The annotation for the return type of the function if specified.
      If the function has no annotation for its return type, this
      attribute is not set.
  * bind(*args, **kwargs) -> BoundArguments
      Creates a mapping from positional and keyword arguments to
      parameters.
  * bind_partial(*args, **kwargs) -> BoundArguments
      Creates a partial mapping from positional and keyword arguments
      to parameters (simulating 'functools.partial' behavior.)
code: def parameters(self):
      try:
          return types.MappingProxyType(self._parameters)
      except AttributeError:
          return OrderedDict(self._parameters.items())
  
imports: from __future__ import absolute_import, division, print_function
  import itertools
  import functools
  import re
  import types
label_desc: Use image node_id 3 for calling the Signature obj's underlying member method code with example usage: obj.parameters() and returns: types, OrderedDict