How to work out 'checkpoint of stake modifiers'?

Hi All

Im deving for other coins at the moment, can someone tell me how to work out the 'checkpoint of stake modifier' values within kernel.cpp ?

This is for one of those oh so popular PoS coins at the moment Wink

Code:

// Hard checkpoints of stake modifiers to ensure they are deterministic
static std::map mapStakeModifierCheckpoints =
boost::assign::map_list_of
( 0, 0xfd11f4e7u )
;