@NotNull
  private static String getStaleInputIdsMessage(Int2ObjectMap<String> staleTrees, IndexId<?, ?> indexId) {
    return "`" + indexId + "` index contains several stale file ids (size = "
           + staleTrees.size()
           + "). Ids & paths: "
           + StringUtil.first(staleTrees.toString(), 300, true)
           + ".";
  }
@NotNull
  private static String getStaleInputIdsMessage(Int2ObjectMap<String> staleTrees, IndexId<?, ?> indexId)