static readByte(rawbits, startIndex) {
			let n = rawbits.length - startIndex;
			if (n >= 8) {
				return Decoder.readCode(rawbits, startIndex, 8);
			}
			return Decoder.readCode(rawbits, startIndex, n) << (8 - n);
		}
Reads a code of length 8 in an array of bits, padding with zeros