code: def _expect_extra(expected, present, exc_unexpected, exc_missing, exc_args):
      
      if present:
          if not expected:
              raise exc_unexpected(*exc_args)
      elif expected and expected is not Argument.ignore:
          raise exc_missing(*exc_args)
docs: Checks for the presence of an extra to the argument list. Raises expections
      if this is unexpected or if it is missing and expected.