code: private TaskOperationProtocol getTaskManagerProxy() throws IOException {
  
  		if (this.taskManager == null) {
  
  			this.taskManager = RPC.getProxy(TaskOperationProtocol.class,
  				new InetSocketAddress(getInstanceConnectionInfo().address(),
  					getInstanceConnectionInfo().ipcPort()), NetUtils.getSocketFactory());
  		}
  
  		return this.taskManager;
  	}
docs: Creates or returns the RPC stub object for the instance's task manager.
  
  @return the RPC stub object for the instance's task manager
  @throws IOException
  thrown if the RPC stub object for the task manager cannot be created