code: def create_tx(self, txins=None, txouts=None, lock_time=0):
          
          txins = [] if txins is None else txins
          txouts = [] if txouts is None else txouts
          lock_time = deserialize.positive_integer(lock_time)
          txins = deserialize.txins(txins)
          txouts = deserialize.txouts(self.testnet, txouts)
          tx = control.create_tx(self.service, self.testnet, txins, txouts,
                                 lock_time=lock_time)
          return serialize.tx(tx)
docs: Create unsigned rawtx with given txins/txouts as json data.
          <txins>: '[{"txid" : hexdata, "index" : integer}, ...]'
          <txouts>: '[{"address" : hexdata, "value" : satoshis}, ...]'