title: Get wikipedia page url by pageId
body: <p>I use <a href="https://www.mediawiki.org/wiki/API:Main_page" rel="nofollow">wikipedia api</a> to get an extract from a random page.</p>
  
  <p>There is example response:</p>
  
  <pre><code>{
      "batchcomplete": "",
      "continue": {
          "grncontinue": "0.701350797294|0.701351244349|4312122|0",
          "continue": "grncontinue||"
      },
      "query": {
          "pages": {
              "1485573": {
                  "pageid": 1485573,
                  "ns": 0,
                  "title": "some title",
                  "extract": "some text"
              }
          }
      }
  }
  </code></pre>
  
  <p>And now I know <code>pageid</code> of this page. </p>
  
  <p><strong>How</strong> can I get <code>url</code> of this page by <code>pageid</code>?</p>