Set<String> (Project project, Set<VirtualFile> files) { Set<String> ids = new HashSet<>(); for (VirtualFile file : files) { final Set<String> keys = FileBasedIndex.getInstance().getFileData(NAME, file, project).keySet(); final String pluginId = findPluginId(keys); ContainerUtil.addIfNotNull(ids, pluginId); ids.addAll(ContainerUtil.filter(keys, s -> !StringUtil.startsWith(s, PLUGIN_ID_KEY_PREFIX) && !StringUtil.startsWith(s, FILENAME_KEY_PREFIX))); } return ids; }