Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
2 Level 4 Dragon monsters Once per turn: You can detach 1 material from this card; Special Summon 1 Dragon monster from your hand. Your opponent cannot target other "Galaxy" cards you control with card effects, also those cards cannot be destroyed by your opponent's card effects.
--銀河影竜
--Galaxy Stealth Dragon
local s,id=GetID()
function s.initial_effect(c)
	--Xyz summon procedure
	Xyz.AddProcedure(c,aux.FilterBoolFunctionEx(Card.IsRace,RACE_DRAGON),4,2)
	c:EnableReviveLimit()
	--Special Summon 1 Dragon from hand
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e1:SetType(EFFECT_TYPE_IGNITION)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCountLimit(1)
	e1:SetCost(Cost.DetachFromSelf(1))
	e1:SetTarget(s.sptg)
	e1:SetOperation(s.spop)
	c:RegisterEffect(e1)
	--Prevent effect target
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_FIELD)
	e2:SetCode(EFFECT_CANNOT_BE_EFFECT_TARGET)
	e2:SetRange(LOCATION_MZONE)
	e2:SetProperty(EFFECT_FLAG_IGNORE_IMMUNE)
	e2:SetTargetRange(LOCATION_ONFIELD,0)
	e2:SetTarget(s.tgtg)
	e2:SetValue(aux.tgoval)
	c:RegisterEffect(e2)
	--Prevent destruction by opponent's effect
	local e3=Effect.CreateEffect(c)
	e3:SetType(EFFECT_TYPE_FIELD)
	e3:SetCode(EFFECT_INDESTRUCTABLE_EFFECT)
	e3:SetRange(LOCATION_MZONE)
	e3:SetTargetRange(LOCATION_ONFIELD,0)
	e3:SetTarget(s.tgtg)
	e3:SetValue(aux.indoval)
	c:RegisterEffect(e3)
end
s.listed_series={SET_GALAXY}
function s.spfilter(c,e,tp)
	return c:IsRace(RACE_DRAGON) and c:IsCanBeSpecialSummoned(e,0,tp,false,false)
end
function s.sptg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and Duel.IsExistingMatchingCard(s.spfilter,tp,LOCATION_HAND,0,1,nil,e,tp) end
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,nil,1,tp,LOCATION_HAND)
end
function s.spop(e,tp,eg,ep,ev,re,r,rp)
	if Duel.GetLocationCount(tp,LOCATION_MZONE)<=0 then return end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SPSUMMON)
	local g=Duel.SelectMatchingCard(tp,s.spfilter,tp,LOCATION_HAND,0,1,1,nil,e,tp)
	if #g>0 then
		Duel.SpecialSummon(g,0,tp,tp,false,false,POS_FACEUP)
	end
end
function s.tgtg(e,c)
	return c:IsSetCard(SET_GALAXY) and c~=e:GetHandler()
end