def __contains__(self, name):
        "This function is used by the 'in' keyword"
        retval = True
        for pos in self._hashes(name):
            retval = retval and bool(self.hash & (2 ** pos))
        return retval
def __contains__ ( self , name ) : retval = True for pos in self . _hashes ( name ) : retval = retval and bool ( self . hash & ( 2 ** pos ) ) return retval
This function is used by the 'in' keyword