void (String id, Collection<? extends VirtualFile> files) { synchronized (myLock) { IntSet set = null; try { set = myExistentFrameworkFiles.get(id); } catch (IOException e) { LOG.info(e); } if (set == null) { set = new IntOpenHashSet(); try { myExistentFrameworkFiles.put(id, set); } catch (IOException e) { LOG.info(e); } } for (VirtualFile file : files) { set.add(FileBasedIndex.getFileId(file)); } } }