@Override
    public HelixClusterManager getClusterMap() throws IOException {
      return mock(HelixClusterManager.class);
    }
Deep copy a {@link DataNodeConfig}.
@param dataNodeConfig {@link DataNodeConfig} to copy
@return {@link InstanceConfig} of given data node.
ambry-clustermap/src/test/java/com/github/ambry/clustermap/HelixParticipantTest.java