'Get the milestone indicated by ``number``.
:param int number: (required), unique id number of the milestone
:returns: :class:`Milestone <github3.issues.milestone.Milestone>`'

def milestone(self, number):

    json = None
    if (int(number) > 0):
        url = self._build_url(u'milestones', str(number), base_url=self._api)
        json = self._json(self._get(url), 200)
    return self._instance_or_null(Milestone, json)
