best way to know if an unitid is valid or not ?

library IsUnitIdValid uses IsGameLoaded

globals
   private unit U
endglobals

function IsUnitIdValid takes integer i returns boolean
    if IsGameLoaded() then // ofc i plan to store the result, to avoid the creation of the unit all the time, when it was already checked
                           // but i'm waiting for hashtables available on the official patch
        set U = CreateUnit(Player(0),i,0.,0.,0.) // yeah i should use a dummy player and constants reals X/Y instead
        
        if GetWidgetLife(U) != 0 then
            call RemoveUnit(U)
            return true
        else
            return false
        endif
        
    else
    
        return UnitId2String(i) != null
    endif
endfunction

endlibrary

library IsGameLoaded initializer init

globals
    private boolean B = false
endglobals

function IsGameLoaded takes nothing returns boolean
    return B
endfunction

private function Actions takes nothing returns nothing
    set B = true
endfunction

private function init takes nothing returns nothing
    local trigger trig = CreateTrigger()
    call TriggerRegisterGameEvent(trig,EVENT_GAME_LOADED)
    call TriggerAddAction(trig,function Actions)
endfunction

endlibrary