xxxxx.xxxxx.keywords.add
        ===================================
        创建一批关键词

def add(self, adgroup_id, keyword_prices, nick=None):
        '''xxxxx.xxxxx.keywords.add
        ===================================
        创建一批关键词'''
        request = TOPRequest('xxxxx.xxxxx.keywords.add')
        request['adgroup_id'] = adgroup_id
        request['keyword_prices'] = keyword_prices
        if nick!=None: request['nick'] = nick
        self.create(self.execute(request), models = {'result':Keyword})
        return self.result