question: public void indexNode ( CommonTree node , List < CompilationUnit > list ) { if ( node == null ) { return ; } if ( node instanceof DelphiPMDNode ) { list . add ( ( DelphiPMDNode ) node ) ; } else { list . add ( new DelphiPMDNode ( node ) ) ; } for ( int i = 0 ; i < node . getChildCount ( ) ; ++ i ) { indexNode ( ( CommonTree ) node . getChild ( i ) , list ) ; } }
target:  Adds children nodes to list