Async.invoke_later has no scheduler

[mmerickel]

promise/promise/async_.py

Lines 40 to 44 in d80d791

	def invoke_later(self, fn):
	if self.trampoline_enabled:
	self._async_invoke_later(fn, scheduler)
	else:
	scheduler.call_later(0.1, fn)

Just from visual inspection this code is dependent on a scheduler variable that is not defined anywhere in scope.