Use a provided external context

{
  "@vocab": "http://example.com/vocab#",
  "one": "http://example.com/one#",
  "two": "ex:test/",
  "three": "ex:test_"
}

-

{
  "zero": ["bar"],
  "one:foo": {
    "two:foo": [
      { "three:foo:bar": "baz" }
    ]
  }
}

{
  "http://example.com/vocab#zero": ["bar"],
  "http://example.com/one#foo": {
    "ex:test/foo": [
      { "ex:test_foo:bar": "baz" }
    ]
  }
}