':calls: `GET /repos/:owner/:repo/git/tags/:sha <http://developer.github.com/v3/git/tags>`_
:param sha: string
:rtype: :class:`github.GitTag.GitTag`'

def get_git_tag(self, sha):

    assert isinstance(sha, (str, unicode)), sha
    (headers, data) = self._requester.requestJsonAndCheck('GET', ((self.url + '/git/tags/') + sha))
    return github.GitTag.GitTag(self._requester, headers, data, completed=True)
