component = {
type = function (address)
        if address == FS1 then return "filesystem"
        elseif address == SCREEN then return "screen"
        else
                print("unknown addr",address)
        end
end
}
function component.proxy(address)
        print(debug.traceback())
        print(component.type)
        local type, reason = spcall(component.type, address)
        if not type then
                return nil, reason
        end
end