Double Diminishing Returns?

Hi!

How can I add two Diminishing Returns to a spell in this function?

SpellMgr.cpp

DiminishingGroup [COLOR=rgb(121,93,163)]GetDiminishingReturnsGroupForSpell(SpellInfo [COLOR=rgb(167,29,93)]const* spellproto)

https://github.com/TrinityCore/TrinityCore/blob/6.x/src/server/game/Spells/SpellMgr.cpp#L57

By example:

Add spell X:

[COLOR=rgb(51,51,51)]DIMINISHING_STUN And [COLOR=rgb(51,51,51)]DIMINISHING_DISORIENT

[COLOR=rgb(51,51,51)]Thx