@classmethod
def DeregisterHelper(cls, resolver_helper):
    """Deregisters a path specification resolver helper.

    Args:
      resolver_helper (ResolverHelper): resolver helper.

    Raises:
      KeyError: if resolver helper object is not set for the corresponding
          type indicator.
    """
    if resolver_helper.type_indicator not in cls._resolver_helpers:
        raise KeyError(
            'Resolver helper object not set for type indicator: {0:s}.'.
            format(resolver_helper.type_indicator))
    del cls._resolver_helpers[resolver_helper.type_indicator]
