code: def get_items_of_type(self, item_type):
          
          return (item for item in self.items if item.get_type() == item_type)
docs: Returns all items of specified type.
  
          >>> book.get_items_of_type(epub.ITEM_IMAGE)
  
          :Args:
            - item_type: Type for items we are searching for
  
          :Returns:
            Returns found items as tuple.