ModificationTracker (@NotNull StubFileElementType<?> fileElementType) { return () -> { if (PER_FILE_ELEMENT_TYPE_STUB_CHANGE_TRACKING_SOURCE == PerFileElementTypeStubChangeTrackingSource.ChangedFilesCollector) { ReadAction.run(() -> { ((FileBasedIndexImpl)FileBasedIndex.getInstance()).getChangedFilesCollector().processFilesToUpdateInReadAction(); }); } return myPerFileElementTypeStubModificationTracker.getModificationStamp(fileElementType); }; }