void hide(BitSet bs, boolean isQuiet) {
		bsHidden.and(bsNull);
		if (bs != null)
			bsHidden.or(bs);
		if (viewer.getFrame() != null)
			viewer.getFrame().bsHidden = bsHidden;
		if (!isQuiet)
			viewer.reportSelection(GT._("{0} atoms hidden", "" + viewer.cardinalityOf(bsHidden)));
	}