@Contract(pure = true)
  public static int stringHashCode(@NotNull CharSequence chars, int from, int to, int prefixHash) {
    int h = prefixHash;
    for (int off = from; off < to; off++) {
      h = 31 * h + chars.charAt(off);
    }
    return h;
  }
@Contract(pure = true)
  public static int stringHashCode(@NotNull CharSequence chars, int from, int to, int prefixHash)