code: def thumbnail(self):
          
          if 'THUMBNAIL_RESOURCE' in self.image_resources:
              return pil_io.convert_thumbnail_to_pil(
                  self.image_resources.get_data('THUMBNAIL_RESOURCE')
              )
          elif 'THUMBNAIL_RESOURCE_PS4' in self.image_resources:
              return pil_io.convert_thumbnail_to_pil(
                  self.image_resources.get_data('THUMBNAIL_RESOURCE_PS4'), 'BGR'
              )
          return None
docs: Returns a thumbnail image in PIL.Image. When the file does not
          contain an embedded thumbnail image, returns None.