Function callback

lib/backend.js:231–234

(error, ops)

  var request = new SubmitRequest(this, agent, index, id, op, options);

  var callback = function(error, ops) {
    backend.emit('submitRequestEnd', error, request);
    originalCallback(error, ops, request);
  };

  var err = ot.checkOp(op);
  if (err) return callback(err);