<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def start(self):
 """This method starts a task executing and returns immediately. Subclass should override this method, if it has an asynchronous way to start the task and return immediately. """

        if self.threadPool:
            self.threadPool.addTask(self)

            # Lets other threads have a chance to run
            time.sleep(0)
        else:
            raise TaskError("start(): nothing to start for task %s" % self)