boolean (@NotNull final Project project, @Nullable final PsiFile psiFile) { if (psiFile == null) { return true; } final VirtualFile virtualFile = psiFile.getVirtualFile(); if (virtualFile != null) { final ProjectFileIndex fileIndex = ProjectRootManager.getInstance(project).getFileIndex(); if (fileIndex.isExcluded(virtualFile) || (fileIndex.isInLibraryClasses(virtualFile) && !fileIndex.isInContent(virtualFile))) { return true; } } return false; }