Problem with creating new trinket (code)

Hello! Today ive got idea to create a new trinket with special effect. I want to player take no damage from cursed doors when he has it, but I dont know how to make it real. My item is in game, with name and description but no effect! It's my first mod so... Yea, im amateur in that kind of things but I want to try! Here's my code:

local Mod = RegisterMod( "Mod", 1 );
local GUARDIAN ANGEL = Isaac.GetItemIdByName( "GUARDIAN ANGEL" )

TrinketType.TRINKET_GUARDIAN ANGEL = Isaac.GetTrinketIdByName("GUARDIAN ANGEL")

function Mod:cacheUpdate(player, cacheflag)
local player = Isaac.GetPlayer(0);
if player:HasCollectible(GUARDIAN ANGEL) then
    player.DAMAGE_CURSED_DOOR = "0"
     end
 end

 Mod:AddCallback(ModCallbacks.MC_EVALUATE_CACHE, Mod.onCache)