{ "head": {
    "vars": [ "o1" , "v1" , "o2" , "v2" ]
  } ,
  "results": {
    "bindings": [
      { 
        "o1": { "type": "uri" , "value": "http://example/o" } ,
        "v1": { "type": "literal" , "datatype": "http://www.w3.org/2001/XMLSchema#integer" , "value": "123" }
      }
    ]
  }
}