code: public void modified(List<String> newSources) {
  
          if (collectorMgr == null || isInit == false) {
              this.sourcesList = newSources;
              return;
          }
  
          try {
              //Old sources
              ArrayList<String> oldSources = new ArrayList<String>(sourcesList);
  
              //Sources to remove -> In Old Sources, the difference between oldSource and newSource
              ArrayList<String> sourcesToRemove = new ArrayList<String>(oldSources);
              sourcesToRemove.removeAll(newSources);
              collectorMgr.unsubscribe(this, convertToSourceIDList(sourcesToRemove));
  
              //Sources to Add -> In New Sources, the difference bewteen newSource and oldSource
              ArrayList<String> sourcesToAdd = new ArrayList<String>(newSources);
              sourcesToAdd.removeAll(oldSources);
              collectorMgr.subscribe(this, convertToSourceIDList(sourcesToAdd));
  
              sourcesList = newSources; //new master sourcesList
          } catch (Exception e) {
              e.printStackTrace();
          }
      }
docs: Without osgi, this modified method is called explicility from the update method in
  JsonTrService
  
  @param newSources List of the new source list from config