// If the first bit is set, then all following bits constitute a two's
	// complement encoded number in big-endian byte order.
	if len(b) > 0 && b[0]&0x80 != 0 {
		// Handling negative numbers relies on the following identity:
		//	-a-1 == ^a
		//
		// If the number is negative, we use an inversion mask to invert the
		// data bytes and treat the value as an unsigned number.