@Test
public void testLookupNode() {

  DataCenterSpec dc = new DataCenterSpec();
  dc.addNode().build();
  dc.addNode().build();
  dc.addNode().build();
  // Lookup node by id
  assertThat(dc.node(0).getId()).isEqualTo(0);
  assertThat(dc.node(1).getId()).isEqualTo(1);
  assertThat(dc.node(2).getId()).isEqualTo(2);
  assertThat(dc.node(3)).isNull();
}