def _assertFalseFalse(self, method):
        """
        Perform the positive case test for C{failIf} or C{assertFalse}.

        @param method: The test method to test.
        """
        for notTrue in [0, 0.0, False, None, (), []]:
            result = method(notTrue, "failed on %r" % (notTrue,))
            if result != notTrue:
                self.fail("Did not return argument %r" % (notTrue,))

        Perform the positive case test for C{failIf} or C{assertFalse}.

        @param method: The test method to test.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/test/test_assertions.py