code: def get_task(self, task=0, timeout=None, block=True):
          
          return _NuMapTask(self, task=task, timeout=timeout, block=block)
docs: Returns an iterator which results are limited to one **task**. The 
          default iterator the one which e.g. will be used in a for loop is the
          iterator for the first task (task =0). The returned iterator is a 
          ``_NuMapTask`` instance.
          
          Compare::
  
              for result_from_task_0 in imap_instance:
                  pass
  
          with::
  
              for result_from_task_1 in imap_instance.get_task(task_id =1):
                  pass
  
          a typical use case is::
  
              task_0_iterator = imap_instance.get_task(task_id =0)
              task_1_iterator = imap_instance.get_task(task_id =1)
  
              for (task_1_res, task_0_res) in izip(task_0_iterator, task_1_iterator):
                  pass