code: def __str__(self):
      return "Id: {}, trial id: {}, training_step: {}".format(
          self.id, self.trial_id, self.training_step
      )
  
file_path: AutoGL/autogl/module/hpo/suggestion/models.py
imports: from __future__ import unicode_literals
label_desc: Use image node_id 1 for calling the TrialMetric obj's underlying member method code with example usage: obj.__str__() and returns: str