move back x times in fragment backstack

BackStackActivity.kt

private fun moveBackXTimes(numOfTimes : Int) {
        if (!lifecycle.currentState.isAtLeast(Lifecycle.State.STARTED))
            return

        val backStackCount = supportFragmentManager.backStackEntryCount
        if (numOfTimes >= backStackCount) {
            throw UnsupportedOperationException("Number of times specified $numOfTimes is greater" +
                    " than the backstackEntryCount")
        }

        val fragment = supportFragmentManager.getBackStackEntryAt(backStackCount - numOfTimes)
        supportFragmentManager.popBackStackImmediate(fragment::class.simpleName, 0)
    }