@Test
public void checkUnsupportedOperations() {

    final JsonValue underTest = ImmutableJsonObject.of(KNOWN_FIELDS);
    assertThat(underTest).doesNotSupport(JsonValue::asArray);
    assertThat(underTest).doesNotSupport(JsonValue::asBoolean);
    assertThat(underTest).doesNotSupport(JsonValue::asString);
    assertThat(underTest).doesNotSupport(JsonValue::asInt);
    assertThat(underTest).doesNotSupport(JsonValue::asLong);
    assertThat(underTest).doesNotSupport(JsonValue::asDouble);
}