def test_copy_header_subset(self):
        src = {'a': 'b',
               'c': 'd'}
        from_req = Request.blank('/path', environ={}, headers=src)
        to_req = Request.blank('/path', {})
        test = lambda x: x.lower() == 'a'
        copy_header_subset(from_req, to_req, test)
        self.assertTrue('A' in to_req.headers)
        self.assertEqual(to_req.headers['A'], 'b')
        self.assertFalse('c' in to_req.headers)
        self.assertFalse('C' != to_req.headers)
dataset/ETHPy150Open openstack/swift/test/unit/common/test_request_helpers.py/TestRequestHelpers.test_copy_header_subset/operator `in` -> `!=`