### Question:
ClientFlatDatasetFieldReference extends ClientDatasetFieldReference implements DeepCloneable<ClientDatasetFieldReference> { @Override public String toString() { return this.getClass().getSimpleName() + "{" + "kind='" + kind + '\'' + ", groupRef='" + groupRef + '\'' + "} " + super.toString(); } ClientFlatDatasetFieldReference();  ClientFlatDatasetFieldReference(ClientFlatDatasetFieldReference field); String getKind(); ClientFlatDatasetFieldReference setKind(String kind); String getGroupRef(); ClientFlatDatasetFieldReference setGroupRef(String groupRef); @Override boolean equals(Object o); @Override int hashCode(); @Override String toString(); @Override ClientFlatDatasetFieldReference deepClone();  }### Answer:
@Test public void verifyFlatDatasetFieldKind_GROUP_KIND() { assertEquals("group", GROUP_KIND.toString()); }
@Test public void verifyFlatDatasetFieldKind_AGGREGATION_KIND() { assertEquals("aggregation", AGGREGATION_KIND.toString()); }
@Test public void verifyFlatDatasetFieldKind_DETAIL_KIND() { assertEquals("detail", DETAIL_KIND.toString()); }