// If the number is negative, we use an inversion mask to invert the
		// data bytes and treat the value as an unsigned number.
		var inv byte // 0x00 if positive or zero, 0xff if negative
		if b[0]&0x40 != 0 {
			inv = 0xff
		}

		var x uint64
		for i, c := range b {
			c ^= inv // Inverts c only if inv is 0xff, otherwise does nothing
			if i == 0 {
				c &= 0x7f // Ignore signal bit in first byte
			}
			if (x >> 56) > 0 {