How would you use the Stopped() Event of an animation track?[SOLVED]

Animation tracks have an event called Stopped() but I dont really know how I would use it, every time I try to use it, it says ("Userdata value") or something.

Anyone know?

Heres the code I have at the moment.

if Choke.Stopped() then
    for _, Parts in pairs(script.Parent:GetChildren()) do
        if Parts and Parts:IsA("Part") or Parts:IsA("UnionOperation") or Parts:IsA("WedgePart") then
        Parts.Transparency = 0
        end
    end
end

Anyone got any ideas? Thank you for your time :)