Cartalyst\Sentinel\Sentinel::getRequestCredentials PHP Method

    public function getRequestCredentials()
    {
        if ($this->requestCredentials === null) {
            $this->requestCredentials = function () {
                $credentials = [];
                if (isset($_SERVER['PHP_AUTH_USER'])) {
                    $credentials['login'] = $_SERVER['PHP_AUTH_USER'];
                }
                if (isset($_SERVER['PHP_AUTH_PW'])) {
                    $credentials['password'] = $_SERVER['PHP_AUTH_PW'];
                }
                if (count($credentials) > 0) {
                    return $credentials;
                }
            };
        }
        $credentials = $this->requestCredentials;
        return $credentials();
    }

 /**
  * Returns the request credentials.
  *
  * @return array
  */
 public function getRequestCredentials()
 {
     return $this->sentinel->getRequestCredentials();
 }