code: public void updateTask(String jobId, String taskId, TaskConstraints constraints)
              throws BatchErrorException, IOException {
          updateTask(jobId, taskId, constraints, null);
      }
docs: Updates the specified task.
  
  @param jobId
  The ID of the job containing the task.
  @param taskId
  The ID of the task.
  @param constraints
  Constraints that apply to this task. If null, the task is given
  the default constraints.
  @throws BatchErrorException
  Exception thrown when an error response is received from the
  Batch service.
  @throws IOException
  Exception thrown when there is an error in
  serialization/deserialization of data sent to/received from the
  Batch service.