code: def prev(self):
          
  
          if self.total:
              if self.offset - self.limit - self.limit < 0:
                  return self.first
              else:
                  offset = self.offset - self.limit
                  return {'page[offset]': offset, 'page[limit]': self.limit}
          else:
              return None
docs: Generate query parameters for the prev page