old_contents: from server import app
  from server.www.base import mobile_request, must_login
  import server.logic.sync as logic_sync
  
  
  @app.route("/sync", methods=['PUT'])
  @mobile_request
  @must_login
  def sync_data(user_id, sync_token=None, sync_items=[], **kwargs):
      return logic_sync.sync_data(user_id, sync_token, sync_items)
  
new_contents: from server import app
  from server.www.base import mobile_request, must_login
  import server.logic.sync as logic_sync
  
  
  @app.route("/sync", methods=['POST'])
  @mobile_request
  @must_login
  def sync_data(user_id, sync_token=None, sync_items=[], need_pull=True **kwargs):
      return logic_sync.sync_data(user_id, sync_token, sync_items, need_pull)
  
subject: tweak sync api