set method
Set a byte.
@param b byte value to set with @param index index to set
Implementation
@override
void set(int b, int index) {
index *= 2;
rep[index] = hextypes[(b >> 4) & 0xF];
// rep[index] = hextypes[(b >>> 4) & 0xF];
rep[index + 1] = hextypes[b & 0xF];
}