docs: def RegisterCheck(cls, check, source="unknown", overwrite_if_exists=False):
      """Adds a check to the registry, refresh the trigger to check map."""
      if not overwrite_if_exists and check.check_id in cls.checks:
        raise DefinitionError(
            "Check named %s already exists and "
            "overwrite_if_exists is set to False." % check.check_id)
      check.loaded_from = source
      cls.checks[check.check_id] = check
      cls.triggers.Update(check.triggers, check)