@Override
  public void add(final int x) {
    final short hb = Util.highbits(x);
    final int i = highLowContainer.getIndex(hb);
    if (i >= 0) {
      highLowContainer.setContainerAtIndex(i,
          highLowContainer.getContainerAtIndex(i).add(Util.lowbits(x)));
    } else {
      final ArrayContainer newac = new ArrayContainer();
      highLowContainer.insertNewKeyValueAt(-i - 1, hb, newac.add(Util.lowbits(x)));
    }
  }
@ Override public void add ( final int x ) { final short hb = Util . highbits ( x ) ; final int i = highLowContainer . getIndex ( hb ) ; if ( i >= 0 ) { highLowContainer . setContainerAtIndex ( i , highLowContainer . getContainerAtIndex ( i ) . add ( Util . lowbits ( x ) ) ) ; } else { final ArrayContainer newac = new ArrayContainer ( ) ; highLowContainer . insertNewKeyValueAt ( - i - 1 , hb , newac . add ( Util . lowbits ( x ) ) ) ; } }
Add the value to the container (set the value to "true"), whether it already appears or not.

Java lacks native unsigned integers but the x argument is considered to be unsigned.
Within bitmaps, numbers are ordered according to {@link Integer#compareUnsigned}.
We order the numbers like 0, 1, ..., 2147483647, -2147483648, -2147483647,..., -1.

@param x integer value