code: public ServiceFuture<Void> enableAsync(String jobId, final ServiceCallback<Void> serviceCallback) {
          return ServiceFuture.fromHeaderResponse(enableWithServiceResponseAsync(jobId), serviceCallback);
      }
docs: Enables the specified job, allowing new tasks to run.
  When you call this API, the Batch service sets a disabled job to the enabling state. After the this operation is completed, the job moves to the active state, and scheduling of new tasks under the job resumes. The Batch service does not allow a task to remain in the active state for more than 180 days. Therefore, if you enable a job containing active tasks which were added more than 180 days ago, those tasks will not run.
  
  @param jobId The ID of the job to enable.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object