function setmt__gc(t, mt)
    local prox = newproxy(true)
    local mtcopy = {}
    for k, v in pairs(mt) do
    	mtcopy[k] = v
	end
	
    getmetatable(prox).__gc = 
        function() mtcopy.__gc(t) end
    mtcopy[prox] = true
    return setmetatable(t, mtcopy)
end


local iscollected = false
function gctest(self)
	iscollected = true
    print("cleaning up:", self)
end

local mt2 = {__gc = gctest}
test = setmt__gc({}, mt2)
collectgarbage()
assert(not iscollected)

test = nil
collectgarbage()
assert(iscollected)