code: public static long[] clearI(long[] v, int off) {
      final int wordindex = off >>> LONG_LOG2_SIZE;
      v[wordindex] &= ~(1L << off);
      return v;
    }
docs: Clear bit number "off" in v.
  <p>
  Low-endian layout for the array.
  
  @param v Buffer
  @param off Offset to clear