code: public static boolean hasChildren(String url, String markup, String selector, int howMany) {
          ensureMarkup(url, markup);
          Document document = documents.get(url);
          Element element = document.select(selector).first();
          return element != null && element.children().size() == howMany;
  
      }
docs: Checks if the first element matched by the {@code selector} has children and if their number is equal to {@code howMany}.
  
  @param url      the url that identifies the markup
  @param markup   the markup
  @param selector the selector used for retrieval
  @param howMany  the number of expected children
  @return {@code true} if the number of children is equal to {@code howMany}, {@code false} otherwise