'Schedule the given queue entry, if possible.
This method should make necessary database changes culminating in
assigning a host to the given queue entry in the database.  It may
take no action if no host can be assigned currently.
:param queue_entry: a HostQueueEntry DBObject
:param scheduling_utility: a HostSchedulingUtility object'

def schedule_metahost(self, queue_entry, scheduling_utility):

    raise NotImplementedError
