docs: def serialize(self, content):
          """ Serialize to JSON.
  
          :return string: serializaed JSON
  
          """
          worker = JSONSerializer(
              scheme=self.resource,
              options=self.resource._meta.emit_options,
              format=self.resource._meta.emit_format,
              **self.resource._meta.emit_models
          )
          return worker.serialize(content)