private boolean clearBit(int n) {
        int intIndex = n >> 5;
        int maskIndex = n & 0x1f;
        int old = bits[intIndex];
        return ((bits[intIndex] &= clearMask[maskIndex]) != old);
    }
Sets the nth bit to off.
Ghidra/Framework/Generic/src/main/java/ghidra/util/datastruct/BitTree.java