code: public @Nullable Page getPage(@Nullable Predicate<Page> filter, @Nullable Page basePage) {
      List<Page> suffixPages = getPages(filter, basePage);
      if (suffixPages.isEmpty()) {
        return null;
      }
      else {
        return suffixPages.get(0);
      }
    }
docs: Get the first item returned by {@link #getPages(Predicate, Page)} or null if list is empty
  @param filter the resource filter
  @param basePage the suffix path is relative to this page path (null for current page)
  @return the first {@link Page} or null