{
  "type": "project",
  "input": {
    "type": "group",
    "input": {
      "type": "bgp",
      "patterns": [
        {
          "type": "pattern",
          "termType": "Quad",
          "subject": {
            "termType": "Variable",
            "value": "s"
          },
          "predicate": {
            "termType": "NamedNode",
            "value": "http://example/p"
          },
          "object": {
            "termType": "Variable",
            "value": "v"
          },
          "graph": {
            "termType": "DefaultGraph",
            "value": ""
          }
        }
      ]
    },
    "variables": [
      {
        "termType": "Variable",
        "value": "s"
      }
    ],
    "aggregates": []
  },
  "variables": [
    {
      "termType": "Variable",
      "value": "s"
    }
  ]
}