'Removes the executor by the given alias from this scheduler.
:param str|unicode alias: alias of the executor
:param bool shutdown: ``True`` to shut down the executor after removing it'

def remove_executor(self, alias, shutdown=True):

    with self._jobstores_lock:
        executor = self._lookup_executor(alias)
        del self._executors[alias]
    if shutdown:
        executor.shutdown()
    self._dispatch_event(SchedulerEvent(EVENT_EXECUTOR_REMOVED, alias))
