serialize method
Implementation
@override
ByteData serialize() {
var data_ = ByteData(mavlinkEncodedLength);
data_.setUint16(0, reqMessageRate, Endian.little);
data_.setUint8(2, targetSystem);
data_.setUint8(3, targetComponent);
data_.setUint8(4, reqStreamId);
data_.setUint8(5, startStop);
return data_;
}