public static TestHardwareLayout constructInitialHardwareLayoutJSON(String clusterName) throws JSONException {
    return constructInitialHardwareLayoutJSON(clusterName, 6, 18088);
  }
Construct a {@link TestHardwareLayout}
@param clusterName the cluster name of the hardware layout
@return return the constructed layout.
ambry-clustermap/src/test/java/com/github/ambry/clustermap/TestUtils.java