void (Project project, Collection<? extends Module> modules, LanguageLevel languageLevel) { if (!getSettings().acceptedNames.contains(languageLevel.name())) { getSettings().acceptedNames.add(languageLevel.name()); } if (modules != null) { JavaProjectModelModificationService service = JavaProjectModelModificationService.getInstance(project); WriteAction.run(() -> { for (Module module : modules) { if (module != null) { service.changeLanguageLevel(module, languageLevel, false); } else { LanguageLevelProjectExtension projectExtension = LanguageLevelProjectExtension.getInstance(project); projectExtension.setLanguageLevel(languageLevel); } } }); } }