heterogeneous collection in a single Cj response

ordersAndLines-cj.js

{
  "collection" : {
    "href" : "...",
    "items" : [
      {
        "href" : "/orders/1",
        "data" : [...],
        "links" : [
          {"rel" : "type", "href" : "http://example.org/rels#order"}
        ]
      },
      {
        "href" : "/orders/1/line/0",
        "data" : [...],
        "links" : [
          {"rel" : "type", "href" : "http://example.org/rels#line"},
          {"rel" : "collection", "href" : "/orders/1"} 
        ]
      },
      {
        "href" : "/orders/1/line/1",
        "data" : [...],
        "links" : [
          {"rel" : "type", "href" : "http://example.org/rels#line"},
          {"rel" : "collection", "href" : "/orders/1"} 
        ]
      },
      {
        "href" : "/orders/1/line/2",
        "data" : [...],
        "links" : [
          {"rel" : "type", "href" : "http://example.org/rels#line"},
          {"rel" : "collection", "href" : "/orders/1"} 
        ]
      }
    ]
  }
}