def serialized(self):
        to_ret = {}
        for group, requirements in self.items():
            to_ret[group] = [str(requirement) for requirement in requirements]
        return to_ret
def _patsplit(pattern, default):
    """Split a string into the optional pattern kind prefix and the actual
    pattern."""
    if ":" in pattern:
        kind, pat = pattern.split(":", 1)
        if kind in allpatternkinds:
            return kind, pat
    return default, pattern