serialize method
Implementation
@override
BsonBinary serialize() {
var buffer = BsonBinary(messageLength);
writeMessageHeaderTo(buffer);
buffer.writeInt(flags);
_collectionFullName?.packValue(buffer);
buffer.writeInt(numberToSkip);
buffer.writeInt(numberToReturn);
_query.packValue(buffer);
if (_fields != null) {
_fields!.packValue(buffer);
}
buffer.offset = 0;
return buffer;
}