public static void AddByte(this MemoryStream stream, sbyte value)
 {
     byte result;
     if (value == -1) result = 0xFF;
     else result = Convert.ToByte(value);
     stream.AddBytes(new[] { result });
 }
 public static void AddByte(this MemoryStream stream, byte value)
 {
     stream.AddBytes(new[] { value });
 }