'Clear the kind map.  Useful for testing.'

@classmethod
def _reset_kind_map(cls):

    keep = {}
    for (name, value) in cls._kind_map.iteritems():
        if (name.startswith('__') and name.endswith('__')):
            keep[name] = value
    cls._kind_map.clear()
    cls._kind_map.update(keep)
