[
  {
    "@id": "http://example.com/U",
    "@graph": [
      {
        "@id": "http://example.com/Subj1",
        "@type": ["http://example.com/Type"],
        "http://example.com/ref": [{"@id": "http://example.com/U"}],
        "http://example.com/list": [{
          "@list": [
            {"@value": "a"},
            {"@value": "b"}
          ]
        }]
      }
    ],
    "@type": ["http://example.com/Graph"],
    "http://example.com/name": [{"@value": "Graph"}]
  }
]