Retrieve email from access token

For details: https://vk.com/dev/auth_sites

src/Vkontakte.php

@@ -9,7 +9,7 @@
 
 class Vkontakte extends AbstractProvider
 {
-    public $scopes = [];
+    public $scopes = ['email'];
     public $uidKey = 'user_id';
     public $responseType = 'json';
 
@@ -22,10 +22,94 @@ public function urlAccessToken()
     {
         return 'https://oauth.vk.com/access_token';
     }
+
+    public function getAccessToken($grant = 'authorization_code', $params = [])
+    {
+        if (is_string($grant)) {
+            // PascalCase the grant. E.g: 'authorization_code' becomes 'AuthorizationCode'
+            $className = str_replace(' ', '', ucwords(str_replace(['-', '_'], ' ', $grant)));
+            $grant = 'League\\OAuth2\\Client\\Grant\\'.$className;
+            if (! class_exists($grant)) {
+                throw new \InvalidArgumentException('Unknown grant "'.$grant.'"');
+            }
+            $grant = new $grant();
+        } elseif (! $grant instanceof GrantInterface) {
+            $message = get_class($grant).' is not an instance of League\OAuth2\Client\Grant\GrantInterface';
+            throw new \InvalidArgumentException($message);
+        }
+
+        $defaultParams = [
+            'client_id'     => $this->clientId,
+            'client_secret' => $this->clientSecret,
+            'redirect_uri'  => $this->redirectUri,
+            'grant_type'    => $grant,
+        ];
+
+        $requestParams = $grant->prepRequestParams($defaultParams, $params);
+
+        try {
+            switch (strtoupper($this->method)) {
+                case 'GET':
+                    // @codeCoverageIgnoreStart
+                    // No providers included with this library use get but 3rd parties may
+                    $client = $this->getHttpClient();
+                    $client->setBaseUrl($this->urlAccessToken() . '?' . $this->httpBuildQuery($requestParams, '', '&'));
+                    $request = $client->get(null, null, $requestParams)->send();
+                    $response = $request->getBody();
+                    break;
+                    // @codeCoverageIgnoreEnd
+                case 'POST':
+                    $client = $this->getHttpClient();
+                    $client->setBaseUrl($this->urlAccessToken());
+                    $request = $client->post(null, null, $requestParams)->send();
+                    $response = $request->getBody();
+                    break;
+                // @codeCoverageIgnoreStart
+                default:
+                    throw new \InvalidArgumentException('Neither GET nor POST is specified for request');
+                // @codeCoverageIgnoreEnd
+            }
+        } catch (BadResponseException $e) {
+            // @codeCoverageIgnoreStart
+            $response = $e->getResponse()->getBody();
+            // @codeCoverageIgnoreEnd
+        }
+
+        switch ($this->responseType) {
+            case 'json':
+                $result = json_decode($response, true);
+
+                if (JSON_ERROR_NONE !== json_last_error()) {
+                    $result = [];
+                }
+
+                break;
+            case 'string':
+                parse_str($response, $result);
+                break;
+        }
+
+        if (isset($result['error']) && ! empty($result['error'])) {
+            // @codeCoverageIgnoreStart
+            throw new IDPException($result);
+            // @codeCoverageIgnoreEnd
+        }
+
+        $result = $this->prepareAccessTokenResult($result);
+
+        $accessToken = $grant->handleResponse($result);
+
+        // Add email from response
+		if (!empty($result['email'])) {
+            $accessToken->email = $result['email'];
+        }
+		return $accessToken;
+    }
 
     public function urlUserDetails(AccessToken $token)
     {
-        $fields = ['nickname',
+        $fields = ['email',
+            'nickname',
             'screen_name',
             'sex',
             'bdate',
@@ -61,7 +145,7 @@ public function userDetails($response, AccessToken $token)
 
         $user = new User();
 
-        $email = (isset($response->email)) ? $response->email : null;
+        $email = (isset($token->email)) ? $token->email : null;
         $location = (isset($response->country)) ? $response->country : null;
         $description = (isset($response->status)) ? $response->status : null;
 
@@ -89,9 +173,7 @@ public function userUid($response, AccessToken $token)
 
     public function userEmail($response, AccessToken $token)
     {
-        $response = $response->response[0];
-
-        return isset($response->email) && $response->email ? $response->email : null;
+        return (isset($token->email)) ? $token->email : null;
     }
 
     public function userScreenName($response, AccessToken $token)