{
  "@context": {
    "dc": "http://purl.org/dc/elements/1.1/",
    "ex": "http://example.org/vocab#",
    "ex:contains": {
      "@type": "@id"
    },
    "xsd": "http://www.w3.org/2001/XMLSchema#"
  },
  "@id": "http://example.org/test#book",
  "dc:title": "Title",
  "ex:contains": "http://example.org/test#chapter"
}