title: How to specify the default XML element text in OpenAPI (Swagger)?
body: <p>I'm building an OpenAPI (Swagger) 2.0 definition for the following XML payload to use within the Swagger UI:</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;addressElement&gt;
      &lt;key type="RECORD_ID" item="3"&gt;Enter value here&lt;/key&gt;
  &lt;/addressElement&gt;
  </code></pre>
  
  <p>I'm having an issue figuring out how to display the default value 'Enter value here' for the element <code>key</code>. Where would one place this default value in an OpenAPI definition? My definition looks like this:</p>
  
  <pre class="lang-json prettyprint-override"><code>    "definitions": {
       "addressElement": {
        "type": "object",
        "title": "Address Element",
        "properties": {
          "key": {
            "type": "object",
            "properties": {
            "type":{
              "type": "string",
              "example": "RECORD_ID",
              "xml":{
                "attribute": true
              }
            },
            "item":{
              "type": "integer",
              "format": "int64",
              "example": "3",
              "xml":{
                "attribute": true
              }
            }
          }
        },
      },
      "xml": {
        "name": "addressElement"
      }
    }
   }
  </code></pre>