public byte this[int i] {
get {
if (i < 0 || i >= this.size) {
throw new Exception ("invalid idx:" + i + "@get");
}
return this.buffer [i];
}
set {
if (i < 0 || i >= this.size) {
throw new Exception ("invalid idx:" + i + "@set");
}
this.buffer [i] = value;
}
}
}