code: def for_page(self, page, per_page):
          
          start = (page - 1) * per_page
  
          return self[start:start + per_page]
docs: "Paginate" the collection by slicing it into a smaller collection.
  
          :param page: The current page
          :type page: int
  
          :param per_page: Number of items by slice
          :type per_page: int
  
          :rtype: Collection