synchronized @NotNull String @NotNull [] getVisibleIds() {
    String[] ids = new String[myItems.size()];
    int c = 0;
    for (TBItem item : myItems) {
      if (item.myIsVisible) {
        ids[c++] = item.getUid();
      }
    }
    return c == myItems.size() ? ids : Arrays.copyOf(ids, c);
  }
synchronized @NotNull String @NotNull [] getVisibleIds()