code: function(group, bucketingId, userId, logger) {
      var bucketingKey = sprintf('%s%s', bucketingId, group.id);
      var bucketValue = module.exports._generateBucketValue(bucketingKey);
      logger.log(LOG_LEVEL.DEBUG, sprintf(LOG_MESSAGES.USER_ASSIGNED_TO_EXPERIMENT_BUCKET, MODULE_NAME, bucketValue, userId));
      var trafficAllocationConfig = group.trafficAllocation;
      var bucketedExperimentId = module.exports._findBucket(bucketValue, trafficAllocationConfig);
      return bucketedExperimentId;
    }
docs: Returns bucketed experiment ID to compare against experiment user is being called into
  @param {Object} group        Group that experiment is in
  @param {string} bucketingId  Bucketing ID
  @param {string} userId       ID of user to be bucketed into experiment
  @param {Object} logger       Logger implementation
  @return {string} ID of experiment if user is bucketed into experiment within the group, null otherwise