Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If you control 2 or more LIGHT monsters, you can Special Summon this card (from your hand). You can only control 1 "Guardian of Order".
--ガーディアン・オブ・オーダー
--Guardian of Order
local s,id=GetID()
function s.initial_effect(c)
	c:SetUniqueOnField(1,0,id)
	--special summon
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_FIELD)
	e1:SetCode(EFFECT_SPSUMMON_PROC)
	e1:SetProperty(EFFECT_FLAG_UNCOPYABLE)
	e1:SetRange(LOCATION_HAND)
	e1:SetCondition(s.spcon)
	c:RegisterEffect(e1)
end
function s.spfilter(c)
	return c:IsFaceup() and c:IsAttribute(ATTRIBUTE_LIGHT)
end
function s.spcon(e,c)
	if c==nil then return true end
	return Duel.GetLocationCount(c:GetControler(),LOCATION_MZONE)>0
		and	Duel.IsExistingMatchingCard(s.spfilter,c:GetControler(),LOCATION_MZONE,0,2,nil)
end