':calls: `GET /repos/:owner/:repo/compare/:base...:head <http://developer.github.com/v3/repos/commits>`_
:param base: string
:param head: string
:rtype: :class:`github.Comparison.Comparison`'

def compare(self, base, head):

    assert isinstance(base, (str, unicode)), base
    assert isinstance(head, (str, unicode)), head
    (headers, data) = self._requester.requestJsonAndCheck('GET', ((((self.url + '/compare/') + base) + '...') + head))
    return github.Comparison.Comparison(self._requester, headers, data, completed=True)
