Collection<VirtualFile> (@NotNull PsiMethod method, int parameterIndex) { final FileBasedIndex fileBasedIndex = FileBasedIndex.getInstance(); final CommonProcessors.CollectProcessor<VirtualFile> collector = new CommonProcessors.CollectProcessor<>(new ArrayList<>()); GlobalSearchScope searchScope = GlobalSearchScopeUtil.toGlobalSearchScope(method.getUseScope(), method.getProject()); searchScope = searchScope.intersectWith(GlobalSearchScopesCore.projectProductionScope(method.getProject())); fileBasedIndex.getFilesWithKey(JavaNullMethodArgumentIndex.INDEX_ID, Collections.singleton(new JavaNullMethodArgumentIndex.MethodCallData(method.getName(), parameterIndex)), collector, searchScope); return collector.getResults(); }