'Handles a m.presence_accept EDU. Mark a presence invite from a
local or remote user as accepted in a local user\'s presence list.
Starts polling for presence updates from the local or remote user.
Args:
observed_user(UserID): The user to update in the presence list.
observer_user(UserID): The owner of the presence list to update.'

@defer.inlineCallbacks
def accept_presence(self, observed_user, observer_user):

    (yield self.store.set_presence_list_accepted(observer_user.localpart, observed_user.to_string()))
