code: def get_metric_1(self, obj):
      metric = self.metric_list[1]
      if not metric:
          return None
  
      result = obj.metric_dict[metric]
  
      return result
  
imports: from rest_framework import serializers
  from modelchimp.models.experiment_image import ExperimentImage
label_desc: Use image node_id 3 for calling the ExperimentImageSerializer obj's underlying member method code with example usage: obj.get_metric_1(obj) and returns: result, None