@Override
  public @NotNull String @NotNull [] getAllFieldNames() {
    Merger<String> merger = null;
    for (PsiShortNamesCache cache : getCaches()) {
      String[] classes = cache.getAllFieldNames();
      if (classes.length != 0) {
        if (merger == null) merger = new Merger<>();
        merger.add(classes);
      }
    }
    return getMergerResult(merger, ArrayUtilRt.EMPTY_STRING_ARRAY);
  }
@Override
  public @NotNull String @NotNull [] getAllFieldNames()