Request::only PHP Method

        public static function only($keys)
        {
            return \Illuminate\Http\Request::only($keys);
        }

 /**
  * Reset the given user's password.
  *
  * @param  \Illuminate\Http\Request  $request
  * @return \Illuminate\Http\Response
  */
 public function postReset(Request $request)
 {
     $credentials = $request->only('email', 'password', 'password_confirmation');
     $response = Password::reset($credentials, function ($user, $password) {
         $this->resetPassword($user, $password);
     });
     switch ($response) {
         case Password::PASSWORD_RESET:
             return redirect($this->redirectPath());
         default:
             return redirect()->back()->withInput($request->only('email'))->withErrors(['email' => trans($response)]);
     }
 }