function func takes unit u returns nothing
...
endfunction

call TimerStart(t,2.00,function func(u))

function func takes nothing returns nothing
  unit u = LoadUnitHandle(hashtab, GetHandleId(GetExpiredTimer()), 0)
...
  call FlushChildHashtable(hashtab, GetHandleId(GetExpiredTimer()))
  set u = null
endfunction
  
  local timer t = CreateTimer()
  call SaveUnitHandle(hashtab, GetHandleId(t), 0, u)
  call TimerStart(t, 2., false, function func)
  set t = null

//
  hashtable hashtab = InitHashtable()