def parse_diff_revision(self, extended_path, revision_str,
                            *args, **kwargs):

        if extended_path.endswith(os.path.join(os.sep, 'main', '0')):
            revision = PRE_CREATION
        elif (extended_path.endswith('CHECKEDOUT') or
              '@@' not in extended_path):
            revision = HEAD
        else:
            revision = extended_path.rsplit('@@', 1)[1]

        return extended_path, revision
Guess revision based on extended_path.
dataset/ETHPy150Open reviewboard/reviewboard/reviewboard/scmtools/clearcase.py/ClearCaseTool.parse_diff_revision