code: function () {
                             // pop command from queue
                             bilanx.pop();
                             // if cmd.isMonitor then execute callback else emit 'monitor'
                              message = fn( data );
                              return cmd && cmd.isMonitor ?
                                     cmd.zn( false, message, cmd.fn ) :
                                     me.emit( 'monitor', message, Formatters.monitor )
                                     ;
                          }
docs: get queue head