How can I save an Octomap using a launch file?

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I am running Ubuntu 16.04 with ROS kinetic version. Besides, I am using octomap_server package to obtain an octomap and see it in RVIZ. Now, we need to save this generated octomap. For that, I am using the next command:

$ rosrun octomap_server octomap_saver -f file.ot

It works succesfully and I can save the file. My question is: Is it possible to save the octomap from a launch file? How can I do that?

Thanks!