write static method
Store data under key with the given ttl.
Implementation
static Future<void> write(String key, dynamic data, Duration ttl) async {
final expiresAt = DateTime.now().add(ttl);
// L1
_memory[key] = _MemoryEntry(data: data, expiresAt: expiresAt);
// L2
await _box?.put(
key,
_HiveEntry(data: data, expiresAtMs: expiresAt.millisecondsSinceEpoch)
.toMap(),
);
}