public void setByte(byte val, int index) {
			validateIndex(index);
			word &= ~(0xffL << (WORD_SIZE * index));
			long shifted = ((long) val) << (WORD_SIZE * index);
			word |= shifted;
			initialized |= (1 << index);
		}
Initializes the byte at {@code index} and sets its value to 
{@code val}
@param val new value 
@param index index
@throws LowlevelError if the index is invalid
Ghidra/Framework/Emulation/src/main/java/ghidra/pcode/memstate/UniqueMemoryBank.java