------------------
<list>
  <Pair>
    <a class="string">something</a>
    <b class="string">fresh</b>
  </Pair>
  <Pair reference="../Pair[1]"/>
  <Pair>
    <a class="Pair" reference="../../Pair[1]"/>
    <b class="string">fresh</b>
  </Pair>
</list>
------------------
<list id="1">
  <Pair id="2">
    <a class="string">something</a>
    <b class="string">fresh</b>
  </Pair>
  <Pair reference="2"/>
  <Pair id="3">
    <a class="Pair" reference="2"/>
    <b class="string">fresh</b>
  </Pair>
</list>
------------------
<list>
  <Pair>
    <a class="string">something</a>
    <b class="string">fresh</b>
  </Pair>
  <Pair reference="/list/Pair"/>
  <Pair>
    <a class="Pair" reference="/list/Pair"/>
    <b class="string">fresh</b>
  </Pair>
</list>
------------------
[
  {
    "a": {
      "@class": "string",
      "$": "something"
    },
    "b": {
      "@class": "string",
      "$": "fresh"
    }
  },
  {
    "@reference": "../Pair[1]"
  },
  {
    "a": {
      "@class": "Pair",
      "@reference": "../../Pair[1]"
    },
    "b": {
      "@class": "string",
      "$": "fresh"
    }
  }
]
------------------
[
  {
    "@id": "2",
    "a": {
      "@class": "string",
      "$": "something"
    },
    "b": {
      "@class": "string",
      "$": "fresh"
    }
  },
  {
    "@reference": "2"
  },
  {
    "@id": "3",
    "a": {
      "@class": "Pair",
      "@reference": "2"
    },
    "b": {
      "@class": "string",
      "$": "fresh"
    }
  }
]
------------------
[
  {
    "a": {
      "@class": "string",
      "$": "something"
    },
    "b": {
      "@class": "string",
      "$": "fresh"
    }
  },
  {
    "@reference": "/list/Pair"
  },
  {
    "a": {
      "@class": "Pair",
      "@reference": "/list/Pair"
    },
    "b": {
      "@class": "string",
      "$": "fresh"
    }
  }
]