code: function defaultClientIDHandler(args, context, info) {
    return get(args, [ 'clientID' ]) ||
      get(context, [ 'clientID' ]) ||
      get(info, [ 'rootValue', 'clientID' ]);
  }
docs: Default client id handler checks args then context
  then rootValue for a clientID field to use
  @param {*} args
  @param {*} context
  @param {*} info