def test_validate(self):
        fixture = {
            'foo': lambda val: val is True
        }

        self.assertTrue(
            validator.validate({'foo': True}, fixture))
        self.assertFalse(
            validator.validate({'foo': False}, fixture))

    def test_only_tests_intersect(self):
        """Test that validator.validate only tests the intersect of keys
        from args and validator.
        """

        fixture = {"foo": lambda val: True, "bar": lambda val: True}

        self.assertTrue(validator.validate({"foo": True}, fixture))
        self.assertTrue(validator.validate({"foo": True, "bar": True}, fixture))
        self.assertTrue(validator.validate({"foo": True, "bar": True, "baz": True}, fixture))

 def test_default_validator(self):
     expect_pass = {
         'attribute': 'foobar'
     }
     self.assertTrue(validator.validate(expect_pass,
                                        validator.DEFAULT_VALIDATOR))
     expect_fail = {
         'attribute': 0
     }
     self.assertFalse(validator.validate(expect_fail,
                                         validator.DEFAULT_VALIDATOR))

 def __call__(self, req):
     if validator.validate(req.environ['ec2.request'].args,
                           validator.DEFAULT_VALIDATOR):
         return self.application
     else:
         raise webob.exc.HTTPBadRequest()