[{
  "http://example.org/input": [{
    "@id": "http://example.com/g1",
    "@graph": [{
      "http://example.org/value": [{"@value": "x"}]
    }]
  }, {
    "@id": "http://example.com/g2",
    "@graph": [{
      "http://example.org/value": [{"@value": "y"}]
    }]
  }]
}]