@Test
@DisplayName("$.* : root is list, objects are rows, nested maps")
public void testListOfNestedObjects() {

    String json = "[{\"a\":1, \"b\":{\"x\":1, \"y\":2}},{\"a\":2, \"b\":{\"x\":3, \"y\":4}}]";
    DataFrame df = Json.loader().load(json);
    Map<String, Object> expectedMap1 = new HashMap<>();
    expectedMap1.put("x", 1);
    expectedMap1.put("y", 2);
    Map<String, Object> expectedMap2 = new HashMap<>();
    expectedMap2.put("x", 3);
    expectedMap2.put("y", 4);
    new DataFrameAsserts(df, "a", "b")
            .expectHeight(2)
            .expectRow(0, 1, expectedMap1)
            .expectRow(1, 2, expectedMap2);
}