@NotNull
  private static String getStringWord(@NotNull String string, int from, @NotNull Int2IntFunction nextIntFun) {
    StringBuilder builder = new StringBuilder();
    int nextInt = from;
    while (nextInt >= 0 && nextInt < string.length() && Character.isLetter(string.charAt(nextInt))) {
      builder.append(string.charAt(nextInt));
      nextInt = nextIntFun.applyAsInt(nextInt);
    }
    return builder.toString();
  }
@NotNull
  private static String getStringWord(@NotNull String string, int from, @NotNull Int2IntFunction nextIntFun)