question: private void reconcilePositions ( XtextResource resource ) { MergingHighlightedPositionAcceptor acceptor = new MergingHighlightedPositionAcceptor ( calculator ) ; acceptor . provideHighlightingFor ( resource , this ) ; List < AttributedPosition > oldPositions = removedPositions ; List < AttributedPosition > newPositions = new ArrayList < AttributedPosition > ( removedPositionCount ) ; for ( int i = 0 , n = oldPositions . size ( ) ; i < n ; i ++ ) { AttributedPosition current = oldPositions . get ( i ) ; if ( current != null ) newPositions . add ( current ) ; } removedPositions = newPositions ; }
target:  Reconcile positions based on the AST subtrees