code: def set_cover(self, file_name, content, create_page=True):
          
  
          # as it is now, it can only be called once
          c0 = EpubCover(file_name=file_name)
          c0.content = content
          self.add_item(c0)
  
          if create_page:
              c1 = EpubCoverHtml(image_name=file_name)
              self.add_item(c1)
  
          self.add_metadata(None, 'meta', '', OrderedDict([('name', 'cover'), ('content', 'cover-img')]))
docs: Set cover and create cover document if needed.
  
          :Args:
            - file_name: file name of the cover page
            - content: Content for the cover image
            - create_page: Should cover page be defined. Defined as bool value (optional). Default value is True.