OpenHAB - Open window timer

import java.util.Map
var file = "windows.rules"

val Map<String, Timer> timers = newHashMap

rule "Notify if window is open too long"
when
    Member of gWarnIfOpen changed
then
    // Always cancel the existing Timer
    val timer = timers.get(triggeringItem.name)
    logInfo(file, "cancelling timer for  " + triggeringItem.name)
    timer?.cancel
    timers.put(triggeringItem.name, null)

    // Create a Timer if the door opened
    if(triggeringItem.state == OPEN) {
        var timerTime = (WindowWarningTime.state as DecimalType).intValue
        logInfo(file, "Setting " + timerTime + " minute timer for " + triggeringItem.name)
        timers.put(triggeringItem.name, createTimer(now.plusMinutes(timerTime), [ |
            logInfo(file, "Sending: " + triggeringItem.label + " ist offen")
            val telegramAction = getActions("telegram","telegram:telegramBot:XXXX")
            telegramAction.sendTelegram("%s ist offen", triggeringItem.label)
        ]))
    }
end