addJS function not working for admin in prestashop

Question

I am trying to add javascript file in prestashop admin using backOfficeHeader hook using a module but nothing happened. My code is given below.

Answer 1

I also met this problem, there is no error and warning, all grammar is right. But cannot find my js File. I found the reason finally. In my case there is nothing in JS file and system passes this file which has no content always.