code: public Observable<InputStream> getFromTaskAsync(String jobId, String taskId, String filePath, FileGetFromTaskOptions fileGetFromTaskOptions) {
          return getFromTaskWithServiceResponseAsync(jobId, taskId, filePath, fileGetFromTaskOptions).map(new Func1<ServiceResponseWithHeaders<InputStream, FileGetFromTaskHeaders>, InputStream>() {
              @Override
              public InputStream call(ServiceResponseWithHeaders<InputStream, FileGetFromTaskHeaders> response) {
                  return response.body();
              }
          });
      }
docs: Returns the content of the specified task file.
  
  @param jobId The ID of the job that contains the task.
  @param taskId The ID of the task whose file you want to retrieve.
  @param filePath The path to the task file that you want to get the content of.
  @param fileGetFromTaskOptions Additional parameters for the operation
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the InputStream object