anchor.diff:      Statement prevStmt = OpType.getPreviousStatement(node, entity);
       if (prevStmt is TryStatement) {
         if (prevStmt.finallyBlock == null) {
  -        _addSuggestion2('on');
  +        _addSuggestion(Keyword.ON);
           _addSuggestion(Keyword.CATCH);
           _addSuggestion(Keyword.FINALLY);
           if (prevStmt.catchClauses.isEmpty) {
  
positive.code:     var obj = entity;
      if (obj is CatchClause ||
          (obj is KeywordToken && obj.value() == Keyword.FINALLY)) {
        _addSuggestion2('on');
        _addSuggestion(Keyword.CATCH);
        return null;
      }
  
negative.code: import 'package:analyzer/dart/ast/visitor.dart';
  import 'package:analyzer/src/dart/ast/token.dart';
  
  const ASYNC_STAR = 'async*';
  const DEFERRED_AS = 'deferred as';
  const EXPORT_STATEMENT = "export '';";
  const IMPORT_STATEMENT = "import '';";
  const PART_STATEMENT = "part '';";
  const SYNC_STAR = 'sync*';
  const YIELD_STAR = 'yield*';
  
  /**
  