PersistentList<EditorHighlighterProvider> (@NotNull String stringKey, final @NotNull FileType key) { PersistentList<EditorHighlighterProvider> fromEP = super.buildExtensions(stringKey, key); if (fromEP.isEmpty()) { checkAddEPListener(); EditorHighlighterProvider defaultProvider = new EditorHighlighterProvider() { @Override public EditorHighlighter getEditorHighlighter(@Nullable Project project, @NotNull FileType fileType, @Nullable VirtualFile virtualFile, @NotNull EditorColorsScheme colors) { return EditorHighlighterFactory.getInstance().createEditorHighlighter( SyntaxHighlighterFactory.getSyntaxHighlighter(fileType, project, virtualFile), colors); } }; return persistentListOf(defaultProvider); } return fromEP; }