put method
Stores response under key.
Implementation
void put(String key, String response, {Duration? ttl}) {
if (_entries.length >= maxEntries) {
// Evict the oldest entry (first inserted, since Dart Maps are insertion
// ordered).
if (_entries.isNotEmpty) _entries.remove(_entries.keys.first);
}
_entries[key] = _CacheEntry(
response,
ttl == null ? null : DateTime.now().add(ttl),
);
}