通过lab03/05其中一个获取刷新令牌(refresh token)
Postman请求：
curl -X POST --user test_client_1:test_secret http://localhost:8080/v1/oauth/tokens -d "grant_type=refresh_token&refresh_token=6fd8d272-375a-4d8a-8d0f-43367dc8b791"
响应案例：
{
"user_id": "6e718e4e-3b17-4cf3-bccd-4b6ee31957c8",
"access_token": "1f962bd5-7890-435d-b619-584b6aa32e6c",
"expires_in": 3600,
"token_type": "Bearer",
"scope": "read_write",
"refresh_token": "3a6b45b8-9d29-4cba-8a1b-0093e8a2b933"
}