How to get the message id after sending a new message with gmail api?

Question

How to get the message id after sending a new message with gmail api ?

function sendMessage(userId, email, callback) {
  var base64EncodedEmail = btoa(email);
  var request = gapi.client.gmail.users.messages.send({
    'userId': userId,
    'message': {
      'raw': base64EncodedEmail
    }
  });
  request.execute(callback);
}

Answer 1

I found the solution : into the callback function we will get an arguments object which contains all the informations about the sent message such as id ,labelId ...ect :

 function callback(){
    var idMail=arguments[0].id;
    /*Stored into the dataBase or others operations */
 }