)

private class ConcurrentMultiMap<K, V> {
    private val map = ConcurrentHashMap<K, MutableSet<V>>()

    fun add(key: K, value: V) =
        map.computeIfAbsent(key, { _ -> ConcurrentHashMap.newKeySet() }).add(value)

    fun getOrEmpty(key: K): Set<V> = map[key] ?: emptySet()
}

abstract class TestFilesCleanupService @Inject constructor(
    private val fileSystemOperations: FileSystemOperations,