[
  {
    "op": "core/blank-down",
    "engineConfig": {
      "facets": [],
      "mode": "row-based"
    },
    "columnName": "key"
  },
  {
    "op": "core/multivalued-cell-join",
    "columnName": "value",
    "keyColumnName": "key",
    "separator": "␟"
  }
]