Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If you Tribute Summon this card, the Tribute must be DARK. If this card is Tributed by a card effect and sent to the GY: Add this card from your GY to your hand.
--死王リッチーロード
--Lich Lord, King of the Underworld
local s,id=GetID()
function s.initial_effect(c)
	--tribute limit
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_TRIBUTE_LIMIT)
	e1:SetValue(s.tlimit)
	c:RegisterEffect(e1)
	--to hand
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_F)
	e2:SetCode(EVENT_RELEASE)
	e2:SetCondition(s.retcon)
	e2:SetTarget(s.rettg)
	e2:SetOperation(s.retop)
	c:RegisterEffect(e2)
end
function s.tlimit(e,c)
	return not c:IsAttribute(ATTRIBUTE_DARK)
end
function s.retcon(e,tp,eg,ep,ev,re,r,rp)
	return e:GetHandler():IsLocation(LOCATION_GRAVE) and e:GetHandler():IsReason(REASON_EFFECT)
end
function s.rettg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	Duel.SetOperationInfo(0,CATEGORY_TOHAND,e:GetHandler(),1,0,0)
end
function s.retop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsRelateToEffect(e) then
		Duel.SendtoHand(c,nil,REASON_EFFECT)
		Duel.ConfirmCards(1-tp,c)
	end
end