/**
  * @param string $username
  * @param string $password
  */
 public function login($username, $password)
 {
     $loginForm = new LoginForm();
     $this->actor->fillField('input[name="' . $loginForm->formName() . '[username]"]', $username);
     $this->actor->fillField('input[name="' . $loginForm->formName() . '[password]"]', $password);
     $this->actor->click('login-button');
 }