human
Complete the below
def delegates(task_that_delegates):

    ''''Lets a task call methods on subtask(s).
    The way this works is that the subtask is run as a part of the task, but
    the task itself doesn\'t have to care about the requirements of the subtasks.
    The subtask doesn\'t exist from the scheduler\'s point of view, and
    its dependencies are instead required by the main task.
    Example:
    .. code-block:: python
    class PowersOfN(luigi.Task):
    n = luigi.IntParameter()
    def f(self, x): return x ** self.n
    @delegates
    class T(luigi.Task):
    def subtasks(self): return PowersOfN(5)
    def run(self): print self.subtasks().f(42)'
    '''
assistant
#Here is Python program to print self.
    if (not hasattr(task_that_delegates, 'subtasks')):
        raise AttributeError(('%s    needs    to    implement    the    method    "subtasks"' % task_that_delegates))
    @task._task_wraps(task_that_delegates)
    class Wrapped(task_that_delegates, ):
        def deps(self):
            return (task.flatten(self.requires()) + task.flatten([t.deps() for t in task.flatten(self.subtasks())]))
        def run(self):
            for t in task.flatten(self.subtasks()):
                t.run()
            task_that_delegates.run(self)
    return Wrapped