def test_append_with_unique(self):

        schema = {
            "mergeStrategy": "append",
            "uniqueItems": True,
        }

        merger = jsonmerge.Merger(schema)

        head = ["a"]
        base = None

        base = merger.merge(base, head)
        base = merger.merge(base, head)

        schema2 = merger.get_schema()

        jsonschema.validate(head, schema2)
        jsonschema.validate(base, schema2)