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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_required_params_for_impression(self, experiment, variation_id):
 """ Get parameters that are required for the impression event to register. Args: experiment: Experiment for which impression needs to be recorded. variation_id: ID for variation which would be presented to user. Returns: Dict consisting of decisions and events info for impression event. """

    snapshot = {}

    snapshot[self.EventParams.DECISIONS] = [{
      self.EventParams.EXPERIMENT_ID: experiment.id,
      self.EventParams.VARIATION_ID: variation_id,
      self.EventParams.CAMPAIGN_ID: experiment.layerId
    }]

    snapshot[self.EventParams.EVENTS] = [{
      self.EventParams.EVENT_ID: experiment.layerId,
      self.EventParams.TIME: self._get_time(),
      self.EventParams.KEY: 'campaign_activated',
      self.EventParams.UUID: str(uuid.uuid4())
    }]

    return snapshot