                               <em>handleCallback</em>
                                </code>
                              </td>
                              <td>
                                <div>
                                  <p>callback function from SmartcarAuth that verifies that no error occured during the OAuth process and extracts the auth code, state string, and virtualKeyUrl upon success. Invokes the completion function with either the code or an error (and state and/or virtualKeyUrl if 