@Test
  public void testGetBothSuccess() {
    DataNodeConfig config = createConfig(1, 1);
    when(primarySource.get(any())).thenReturn(config);
    when(secondarySource.get(any())).thenReturn(config);
    assertEquals("Unexpected response", config, compositeSource.get(config.getInstanceName()));
    verify(primarySource).get(config.getInstanceName());
    verify(secondarySource).get(config.getInstanceName());
  }
Test composite get with both sources returning the same result.
ambry-clustermap/src/test/java/com/github/ambry/clustermap/CompositeDataNodeConfigSourceTest.java