@Test
@DisplayName("$.* : root is object, properties are rows")
public void testObjectProperties() {

    String json = "{\"a\": {\"x\":1, \"y\":2}, \"b\":{\"x\":3, \"y\":4}}";
    DataFrame df = Json.loader().load(json);
    new DataFrameAsserts(df, "x", "y")
            .expectHeight(2)
            .expectRow(0, 1, 2)
            .expectRow(1, 3, 4);
}