def create_empty_revision_as_user(self, username):
        self.assert_is_user(username)
        revisionid = self._nextid
        self._nextid += 1
        self._revisions.append(_Revision(revisionid, username))
        self.set_changed()
        return revisionid
Return the id of a newly created empty revision as 'username'.
dataset/ETHPy150Open bloomberg/phabricator-tools/py/abd/abdt_conduitmock.py/ConduitMockData.create_empty_revision_as_user