anchor.diff:      //   print (folder);
       //   return _resolver;
       // };
  -    
  +
       _context = builder.buildContext(_sourceDirectory.path);
   
   
  
positive.code:   }
  }
  
  class _Error {
    static final _HAS_FIXES_WHITELIST = [
      HintCode.UNUSED_IMPORT,
  
negative.code: 
        // Delete the files
        changeSet = new ChangeSet();
        sourcesList.forEach((s) {
          changeSet.changedContent(s, null);
          changeSet.removedSource(s);
        });
        // Remove sources implicitly created by imports of non-existing files
        changeSet.removedContainer(new _SourceContainer(pathPrefix));
        // _resolver.clear();
        _context.applyChanges(changeSet);
        _ensureAnalysisDone(_context, _MAX_ANALYSIS_DURATION);
  