local group g = CreateGroup()

    set bj_randomSubGroupGroup = g

    set bj_randomSubGroupWant  = count

    set bj_randomSubGroupTotal = CountUnitsInGroup(sourceGroup)

    if (bj_randomSubGroupWant <= 0 or bj_randomSubGroupTotal <= 0) then

        return g

    endif

    set bj_randomSubGroupChance = I2R(bj_randomSubGroupWant) / I2R(bj_randomSubGroupTotal)

    call ForGroup(sourceGroup, function GetRandomSubGroupEnum)

    return g

endfunction