@Contract(pure = true)
  public static int getOccurrenceCount(@NotNull String text, @NotNull String s) {
    int res = 0;
    int i = 0;
    while (i < text.length()) {
      i = text.indexOf(s, i);
      if (i >= 0) {
        res++;
        i++;
      }
      else {
        break;
      }
    }
    return res;
  }
@Contract(pure = true)
  public static int getOccurrenceCount(@NotNull String text, @NotNull String s)