anchor.diff:    }
   
     Future loadSources(Map<String, String> sources) async {
  -    for (String path in sources.keys) {
  -      String source = sources[path];
  -      await sendAddOverlay(path, source);
  -    }
  +    await sendAddOverlays(sources);
       await sendPrioritySetSources(sources.keys.toList());
     }
   
     Future unloadSources(List<String> paths) async {
  -    for (String path in paths) {
  -      await sendRemoveOverlay(path);
  -    }
  +    await sendRemoveOverlays(paths);
     }
   
     /**
  
positive.code:     });
    }
  
    /// Cleanly shutdown the Analysis Server.
    Future shutdown() => serverConnection.sendServerShutdown();
  
    /// Internal implementation of the completion mechanism.
    Future<Map> _completeImpl(Map<String, String> sources,
  
negative.code:     });
    }
  
    Future<EditGetFixesResult> _getFixesImpl(
        Map<String, String> overlays, String path, int offset) async {
      await serverConnection._ensureSetup();
  
      await serverConnection.sendAddOverlays(overlays);
      await serverConnection.analysisComplete.first;
      var fixes = await serverConnection.sendGetFixes(path, offset);
      await serverConnection.sendRemoveOverlays(overlays.keys.toList());
      return fixes;
    }
  
    Future<EditFormatResult> _formatImpl(String src, int offset) async {
      await serverConnection._ensureSetup();
      await serverConnection.sendAddOverlays({mainPath : src});
      await serverConnection.analysisComplete.first;
      var formatResult = await serverConnection.sendFormat(offset);
      await serverConnection.sendRemoveOverlays([mainPath]);
      return formatResult;
    }
  
  