[store_unit]
            [filter]
                type=????????????
                [filter_location]
                    find_in=??????????????
                [/filter_location]
            [/filter]
            variable=shuffle_stack
            kill=yes
        [/store_unit]

        {REVERSE_FOREACH shuffle_stack k}

            [if]
                {VARIABLE_NUMERICAL_GREATER_THAN k 0}
                [then]
                    {VARIABLE_RANDOM r "0..$($k - 1)"}

                    {VARIABLE swap.x $shuffle_stack[$r].x}
                    {VARIABLE swap.y $shuffle_stack[$r].y}

                    {VARIABLE shuffle_stack[$r].x $shuffle_stack[$k].x}
                    {VARIABLE shuffle_stack[$r].y $shuffle_stack[$k].y}

                    {VARIABLE shuffle_stack[$k].x $swap.x}
                    {VARIABLE shuffle_stack[$k].y $swap.y}

                    {CLEAR_VARIABLE swap,r}
                [/then]
            [/if]

            [unstore_unit]
                variable="shuffle_stack[$k]"
                find_vacant=yes
            [/unstore_unit]

            {CLEAR_VARIABLE shuffle_stack[$k]}

        {REVERSE_NEXT k}