':func:`validate_signature_against_kwargs` raises an
``InvalidSignature`` exception if the function takes one argument, but
is passed two arguments.'

def test_one_argument_validation_failure_too_many(self):

    self.assertThat((lambda : validate_signature_against_kwargs(_one_argument_function, set(['arg', 'two']))), _raises_invalid_signature(unexpected_arguments=set(['two'])))
