$ sudo apt-get update
$ sudo apt-get install libcomposereditorng4 

libcomposereditorng4 is installed in your system.

Make ensure the libcomposereditorng4 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libcomposereditorng4 *

You will get with libcomposereditorng4 package name, version, architecture and description in a table

libcomposereditorng4 package basic information: