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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _Enum(docstring, *names):
 """Utility to generate enum classes used by annotations. Args: docstring: Docstring for the generated enum class. *names: Enum names. Returns: A class that contains enum names as attributes. """

  enums = dict(zip(names, range(len(names))))
  reverse = dict((value, key) for key, value in enums.iteritems())
  enums['reverse_mapping'] = reverse
  enums['__doc__'] = docstring
  return type('Enum', (object,), enums)