[FixturesBundle] Change visibility of helper methods

Hi all,

Currently it is not possible to overwrite fixtures because all the helper methods are private. 

For example, I want to create my own fixtures pack in my fixtures bundle (FixturesBundle child, because I dont want to change original code). I want to use sylius fixtures and overwrite them, but I cant.

IMHO helper methods should be protected..
What do you think about this solution?