@Contract(pure = true)
  public static int stringHashCodeIgnoreWhitespaces(@NotNull CharSequence chars) {
    int h = 0;
    for (int off = 0; off < chars.length(); off++) {
      char c = chars.charAt(off);
      if (!isWhiteSpace(c)) {
        h = 31 * h + c;
      }
    }
    return h;
  }
@Contract(pure = true)
  public static int stringHashCodeIgnoreWhitespaces(@NotNull CharSequence chars)