def verify
      differences = expected_calls.keys - actual_calls.keys
      if differences.any?
        raise MockExpectationError, "expected #{differences.first.inspect}"
      else
        true
      end
    end
def verify
      differences = expected_calls.keys - actual_calls.keys
      if differences.any?
        raise MockExpectationError, "expected #{differences.first.inspect}"
      else
        true
      end
    end
Verify that all methods were called as expected. Raises
 +MockExpectationError+ if not called as expected.