Moved sendInviteMessage to a new module in logic/helper/notifications.py. Renamed sendInviteMessage to sendInviteNotification. Removed the now obsolete imports in logic/models/request.py. This has been done to keep the models/logic modules clean.

from django.dispatch import Signal

request_started = Signal()
request_finished = Signal()
got_request_exception = Signal(providing_args=["request"])