code: def cart_db():
      
      config = _config_file()
      _config_test(config)
  
      juicer.utils.Log.log_debug("Establishing cart connection:")
      cart_con = MongoClient(dict(config.items(config.sections()[0]))['cart_host'])
      cart_db = cart_con.carts
  
      return cart_db
docs: return a pymongo db connection for interacting with cart objects