private bool IsVerified(long uid, bool isAsync, IsVerifiedCallback callback, Object state)
        {
            var parameterList = new Dictionary<string, string> { { "method", "facebook.users.isVerified" } };
            Utilities.AddOptionalParameter(parameterList, "uid", uid);

            if (isAsync)
            {
                SendRequestAsync<users_isVerified_response, bool>(parameterList, new FacebookCallCompleted<bool>(callback), state);
                return false;
            }

            var response = SendRequest<users_isVerified_response>(parameterList);
            return response == null ? true : response.TypedValue;
        }
 /// <summary>
 /// Returns whether the user is a verified Facebook user.
 /// </summary>
 /// <example>
 /// <code>
 /// private static void RunDemoAsync()
 /// {
 ///     Api api = new Api(new DesktopSession(Constants.ApplicationKey, Constants.ApplicationSecret, Constants.ApplicationSecret, Constants.SessionKey));
 ///     api.Users.IsVerifiedAsync(Constants.UserId, AsyncDemoCompleted, null);
 /// }
 ///
 /// private static void AsyncDemoCompleted(bool result, Object state, FacebookException e)
 /// {
 ///     var actual = result;
 /// }
 /// </code>
 /// </example>
 /// <param name="uid">The user ID to verify.</param>
 /// <param name="callback">The AsyncCallback delegate</param>
 /// <param name="state">An object containing state information for this asynchronous request</param>        
 /// <returns>This call returns true for a verified user; false for an non-verified user.</returns>
 /// <remarks>This method is currently broken on Facebook's side (it only returns an empty XML element). A bug report has been filed here: http://bugs.developers.facebook.com/show_bug.cgi?id=5129 .</remarks>
 public void IsVerifiedAsync(long uid, IsVerifiedCallback callback, Object state)
 {
     IsVerified(uid, true, callback, state);
 }