I wonder if there is a more idiomatic/concise way to return to the first success result or the last failure.

I have forEach loop with an auxiliary variable and let:

    @Test
    fun `find first success`() {

        val keysToTry = listOf("foo", "bar", "baz")

        val result = returnFirstSuccess(keysToTry)
    }

    fun returnFirstSuccess(keys: List<String>): Result {
        var lastTry : Result? = null
        keys.forEach { key ->
            tryKey(key).let { result ->
                if (result is Result.Success) {
                    return result
                }else{
                    lastTry = result
                }
            }
        }

        return lastTry!!
    }

    fun tryKey(key: String): Result {
        // if key passes return Sucess, otherwise Failure
    }

    sealed class Result {
        object Success : Result()
        data class Failure(val message: String) : Result()
    }