How to convert sensor_msgs/LaserScan.msg to sensor_msgs/MultiEchoLaserScan.msg

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Hello,

I have a node that publish /scan topic and this topic has the massage type sensor_msgs/LaserScan.msg. another node can only subscribe sensor_msgs/MultiEchoLaserScan.msg massage type. The two massage type are very similar only ranges and intensities are different.

I thought I'd make a new node and this node convert the msg. My problem is, i have now idea how can i publich my convert message again. this code is my node "convert_LaserScan_to_MultiEchoLaserScan":

#include "ros/ros.h"
#include "std_msgs/String.h"
#include "sensor_msgs/LaserScan.h"
#include "sensor_msgs/MultiEchoLaserScan.h"

class convert_LaserScan_to_MultiEchoLaserScan
 {
 public:
 convert_LaserScan_to_MultiEchoLaserScan()
  {
 //Topic you want to publish
  pub_ = n_.advertise<sensor_msgs::LaserScan>("/horizontal_laser_2d", 1000);

//Topic you want to subscribe
  sub_ = n_.subscribe("/scan", 1000, &convert_LaserScan_to_MultiEchoLaserScan::callback, this);
 }


 void callback(const sensor_msgs::LaserScan::ConstPtr& input)
{
sensor_msgs::LaserScan output;

sensor_msgs::MultiEchoLaserScan muls;
for (int i = 0; i < input->ranges.size(); ++i) {
    const float &range = input->ranges[i];
    ROS_INFO("ranges: [%f]",range);
    sensor_msgs::LaserEcho echo;
    echo.echoes.push_back(range);
    muls.ranges.push_back(echo);

}

pub_.publish(output);
 }

  private:
  ros::NodeHandle n_;
  ros::Publisher pub_;
  ros::Subscriber sub_;

  };//End of class convert_LaserScan_to_MultiEchoLaserScan


  int main(int argc, char **argv)
 {  
  //Initiate ROS
  ros::init(argc, argv, "convert_LaserScan_to_MultiEchoLaserScan");

  //Create an object of class SubscribeAndPublish that will take care of everything
  convert_LaserScan_to_MultiEchoLaserScan SAPObject;

  ros::spin();



  return 0;
}

I am grateful for your help