title: Jolt JSON Conversion from String value to Long
body: <p>I am using Jolt to convert one json to another json. Everything is working fine except I want to convert String value to Long. Below is my Specs and input. I have use <strong>modify-overwrite-beta</strong> but no luck.</p>
  
  <pre><code>Specs -  
  
  [  
    {
      "operation": "modify-overwrite-beta",
      "spec": {
         "timestamp": "=toLong(@(1,time))"
      }
    },
    {
      "operation": "shift",
      "spec": {
        "key1": "outputText1",
        "key2": "outputText2",
        "key3": "outputText3",
        "time": "timestamp"     
     }
   }
  ]
  
  Input Json
  
  {
     "key1": "test1",
     "time": "1499967627",
     "key2": "test2",
     "key3": "test3",
  }
  </code></pre>
  
  <p>So in above input json how I can convert <strong>time</strong> value to <strong>Long</strong></p>
  
  <p>Expected Json :</p>
  
  <pre><code>{
     "outputText1": "test1",
     "timestamp": 1499967627,
     "outputText2": "test2",
     "outputText3": "test3",
  }
  </code></pre>