code: def extract_meta(cls, serializer, resource):
          
          if hasattr(serializer, 'child'):
              meta = getattr(serializer.child, 'Meta', None)
          else:
              meta = getattr(serializer, 'Meta', None)
          meta_fields = getattr(meta, 'meta_fields', [])
          data = OrderedDict()
          for field_name in meta_fields:
              data.update({
                  field_name: resource.get(field_name)
              })
          return data
docs: Gathers the data from serializer fields specified in meta_fields and adds it to
          the meta object.