{
  "@context": {
    "e": "http://example.org/vocab#",
    "e:A": {"@type": "@id"},
    "e:B": {"@type": "@id"},
    "e:next": {"@type": "@id"}
  },
  "@graph": [
    {
      "@id": "e:test",
      "e:A": "_:b1",
      "e:B": "_:b2"
    },
    {
      "@id": "_:b1",
      "e:next": "_:b3"
    },
    {
      "@id": "_:b2",
      "e:next": "_:b3"
    },
    {
      "@id": "_:b3"
    }
  ]
}