code: func NewMsgTx(version int32) *MsgTx {
  	return &MsgTx{
  		Version: version,
  		TxIn:    make([]*TxIn, 0, defaultTxInOutAlloc),
  		TxOut:   make([]*TxOut, 0, defaultTxInOutAlloc),
  	}
  }
docs: // NewMsgTx returns a new bitcoin tx message that conforms to the Message
  // interface.  The return instance has a default version of TxVersion and there
  // are no transaction inputs or outputs.  Also, the lock time is set to zero
  // to indicate the transaction is valid immediately as opposed to some time in
  // future.