@Override
  public void setInstanceOperation(String clusterName, String instanceName,
      InstanceConstants.InstanceOperation instanceOperation) {
    setInstanceOperation(clusterName, instanceName, instanceOperation, "Not Implemented");
  }
@return the number of calls to the {@link #setInstanceConfig} method.
ambry-clustermap/src/test/java/com/github/ambry/clustermap/MockHelixAdmin.java