new_contents: from app import app
  
  
  @app.route('/user/article/:id', methods=['GET'])
  def get_article(article_id):
      """
      @api {get} /user/article/:id Get a article
      @apiName Get a article
      @apiGroup Article
  
      @apiHeader {String} Access-Token Access token obtains from Oauth2 provider.
      @apiHeader {String} Provider-Name Oauth2 provider name.
      @apiHeaderExample {json} Header (Example):
          {
              "Access-Token": "12xsdklajlkadsf",
              "Provider-Name": "Google"
          }
  
      @apiParam {String} id Article unique ID.
  
      @apiSuccess {String} id Article id.
      @apiSuccess {String} title Article title.
      @apiSuccess {String} list_id List id.
      @apiSuccess {Object[]} comments User comments.
      @apiSuccess {Object} comments.content The content.
      @apiSuccess {String} comments.timestamp The timestamp of the comment.
      @apiSuccessExample {json} Response (Example):
          {
              "id": "aldkfjadls",
              "title": "Process",
              "list_id": "ladsjflas",
              "comments" : [{
                  "content": "i hate it",
                  "timestamp": "2017-02-04-19-59-59"
              }]
          }
      """
      pass
  
  # TODO more resources for articles
  
subject: add router controller for ‘article’ endpoint