public @NotNull String dumpToString() {
    String[] idToValueLocal = idToValue;
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < idToValueLocal.length; i++) {
      String value = idToValueLocal[i];
      sb.append(value).append(" -> ").append(i + 1).append('\n');
    }
    return sb.toString();
  }
public @NotNull String dumpToString()