writeUTF method
Implementation
void writeUTF(String s, [Endian endian = Endian.big]) {
List<int> bytesNeeded = utf8.encode(s);
if (bytesNeeded.length > 65535)
throw FormatException("Length cannot be greater than 65535");
writeShort(bytesNeeded.length, endian);
write(bytesNeeded);
}