M method
Implementation
MfuncTuple M(Uint8List candidbytes, CandidBytes_i start_i) {
FindLeb128BytesTuple sleb128_bytes_tuple = find_leb128bytes(candidbytes, start_i);
BigInt sleb128_int = leb128.decodeSigned(sleb128_bytes_tuple.item1);
return MfuncTuple(Int(sleb128_int), sleb128_bytes_tuple.item2);
}