Get iterator for all unicode code points contained in this range group.

        :yields: iterator of character index (int)
        :ytype: int

def codes(self):
        '''
        Get iterator for all unicode code points contained in this range group.

        :yields: iterator of character index (int)
        :ytype: int
        '''
        for start, end in self:
            for item in range(start, end):
                yield item