code: def get_variation_for_experiment(self, experiment_id):
      
  
      return self.experiment_bucket_map.get(experiment_id, {self.VARIATION_ID_KEY: None}).get(self.VARIATION_ID_KEY)
docs: Helper method to retrieve variation ID for given experiment.
  
      Args:
        experiment_id: ID for experiment for which variation needs to be looked up for.
  
      Returns:
        Variation ID corresponding to the experiment. None if no decision available.