{
  "source_table": "pis",
  "transformation_type": "sum",
  "grouping_column": "id",
  "absent_default_value": 0,
  "aggregation_column": "num_items",
  "output_feature_name": "num_prescriptions_since_2016",
  "filter": {
    "column": "paid_date",
    "type": "date_gt_eq",
    "value": "2016-01-01"
  }
}
