def test_discard_arraymergebyid_null(self):

        schema = {
                'mergeStrategy': 'arrayMergeById',
                'items': {
                    'mergeStrategy': 'discard'
                } }

        base = [ ]
        head = [ {'id': 1, 'val': 1} ]

        base = jsonmerge.merge(base, head, schema)
        self.assertEqual(base, [])