def _parse_line(self, line):
        parts = line.split(':', 3)
        message = parts[3].strip()
        return (parts[0], int(parts[1]), message)
`rubocop --format emacs` lines look like this:
dataset/ETHPy150Open markstory/lint-review/lintreview/tools/rubocop.py/Rubocop._parse_line