':calls: `GET /repos/:owner/:repo/git/refs/:ref <http://developer.github.com/v3/git/refs>`_
:param ref: string
:rtype: :class:`github.GitRef.GitRef`'

def get_git_ref(self, ref):

    prefix = '/git/refs/'
    if (not self._requester.FIX_REPO_GET_GIT_REF):
        prefix = '/git/'
    assert isinstance(ref, (str, unicode)), ref
    (headers, data) = self._requester.requestJsonAndCheck('GET', ((self.url + prefix) + ref))
    return github.GitRef.GitRef(self._requester, headers, data, completed=True)
