Is package DocumentManager; a typo or real code? In case it is real code, I think it should be package Mokslas::DocumentManager;. The same holds for the other package declaration.

Without further code, that's all I can say

Ciao!
--bronto

The very nature of Perl to be like natural language--inconsistant and full of dwim and special cases--makes it impossible to know it all without simply memorizing the documentation (which is not complete or totally correct anyway).
--John M. Dlugosz