What is the role of HibernateUtil?

I'm new to Hibernate, and everytime I come across a Hibernate tutorial there is a mention of HibernateUtil class ?

What actually does it do ? And if there is a standard implementation why don't it being included开发者_开发百科 in Hibernate jar itself?

There's an answer here that might suffice.

Looks like they want developers to write their own by design, because the number of possibilities to cover is too large.