title: How to define empty array in swagger
body: <p>I know how to make array of string data in swagger like this:</p>
  
  <pre><code>"photoUrls" : {
      "type":"array",
      "items":{
           "type":"string"
      }
  }
  </code></pre>
  
  <p>It will show output like this:</p>
  
  <pre><code>"photoUrls":[
      "string"
  ]
  </code></pre>
  
  <p>How to make output like this?:</p>
  
  <pre><code>"photoUrls":[]
  </code></pre>