title: Jackson json serializations fails for integer key
body: <p>How do i convert the following JSON into a class in Jackson java</p>
  
  <pre><code>{
    "status": 0,
    "msg": "0 out of 1 Transactions Fetched Successfully",
    "transaction_details": {
      "3690": {
        "mihpayid": "Not Found",
        "status": "Not Found"
      }
    }
  }
  </code></pre>
  
  <p>The integer key in transaction_details causes an issue, we have no control over the format as its returned from a 3rd party payment gateway.</p>