def prefetch(self, txhash, output_set, color_desc, limit):
        url = self.url_stem % "%s/prefetch"
        data = {'txhash': txhash, 'output_set': output_set,
                'color_desc': color_desc, 'limit': limit}
        req = urllib2.Request(url, json.dumps(data),
                              {'Content-Type': 'application/json'})
        f = urllib2.urlopen(req)
        txs = json.loads(f.read())
        for txhash, txraw in txs.items():
            self.tx_lookup[txhash] = txraw
        f.close()
        return
dataset/ETHPy150Open chromaway/ngcccbase/ngcccbase/services/chroma.py/ChromaBlockchainState.prefetch/swapped operands of `%`