title: How to retrieve value from Json string in C#
body: <p>I'm getting a response like </p>
  
  <pre><code>{ "expires": "Sat, 19 May 2046 04:10:58 +0000", "copy_ref": "SMJNA2wxbGZbnmbnm", "Result": null, "error": null }
      base: { "expires": "Sat, 19 May 2046 04:10:58 +0000", "copy_ref": "SMJNA2wxbGZ0aWRibWw2aA", "Result": null, "error": null }
      ContentDisposition: null
      ContentType: "application/json"
      HttpHeaders: {Connection: keep-alive
  expires=Tue, 25 May 2021 04:10:58 GMT; 
  }
      IsArray: true
      IsSuccessfully: true
      IsXml: true
      Result: { "expires": "Sat, 19 May 2046 04:10:58 +0000", "copy_ref": "SMJNA2wxbGZbnmbnm", "Result": null, "error": null }
      StatusCode: 200
  </code></pre>
  
  <p>I need the value of "copy_ref" from this response string in C#.</p>