def each_page(indices)
      unless block_given?
        enum_for(:each_page,indices)
      else
        indices.map { |index| yield page_cache[index] }
      end
    end
def each_page(indices)
      unless block_given?
        enum_for(:each_page,indices)
      else
        indices.map { |index| yield page_cache[index] }
      end
    end
Iterates over the pages at the specified indices.

 @param [Array, Range] indices
   The indices.

 @yield [page]
   The given block will be passed each page.

 @yieldparam [Page] page
   A page at one of the given indices.