private long getContextBytes(ParserWalker walker) {
		long res = 0;
		int tmp;
		int size;
		int bs = startbyte;

		size = endbyte - bs + 1;
		while (size >= 4) {
			tmp = walker.getContextBytes(bs, 4);
			res <<= 32;
			res |= tmp;
			bs += 4;
			size = endbyte - bs + 1;
		}
		if (size > 0) {
			tmp = walker.getContextBytes(bs, size);
			res <<= 8 * size;
			res |= tmp;
		}
		return res;
	}
Build a long from the context bytes at the current point in the instruction parse
@param walker is the parsing state
@return the recover value
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/processors/sleigh/expression/ContextField.java