code: function(
    self,
    mongo_auth_process,
    payload,
    db,
    username,
    password,
    authdb,
    server,
    connection,
    callback
  ) {
    // Build the sasl start command
    var command = {
      saslStart: 1,
      mechanism: 'GSSAPI',
      payload: payload,
      autoAuthorize: 1
    };
  
    // Write the commmand on the connection
    server(
      connection,
      new Query(self.bson, '$external.$cmd', command, {
        numberToSkip: 0,
        numberToReturn: 1
      }),
      function(err, r) {
        if (err) return callback(err, false);
        var doc = r.result;
        // Execute mongodb transition
        mongo_auth_process.transition(r.result.payload, function(err, payload) {
          if (err) return callback(err, false);
  
          // MongoDB API Second Step
          MongoDBGSSAPISecondStep(
            self,
            mongo_auth_process,
            payload,
            doc,
            db,
            username,
            password,
            authdb,
            server,
            connection,
            callback
          );
        });
      }
    );
  }
docs: Perform first step against mongodb