public void removeHighlightedNodes(Collection<Tree> nodes) {
		if ( highlightedNodes!=null ) {
			// only remove exact objects defined by ==, not equals()
			for (Tree t : nodes) {
				int i = getHighlightedNodeIndex(t);
				if ( i>=0 ) highlightedNodes.remove(i);
			}
		}
	}
Slow for big lists of highlighted nodes
tool/src/org/antlr/v4/gui/TreeViewer.java