'Return a :class:`compose.container.Container` for this service. The
container must be active, and match `number`.'

def get_container(self, number=1):

    labels = (self.labels() + [u'{0}={1}'.format(LABEL_CONTAINER_NUMBER, number)])
    for container in self.client.containers(filters={u'label': labels}):
        return Container.from_ps(self.client, container)
    raise ValueError((u'No    container    found    for    %s_%s' % (self.name, number)))
