tryPutIfAbsent method
Put if absent with error handling
Implementation
RxResult<V> tryPutIfAbsent(K key, V Function() ifAbsent) {
return RxResult.tryExecute(() {
final newMap = Map<K, V>.from(value);
final sizeBefore = newMap.length;
final result = newMap.putIfAbsent(key, ifAbsent);
if (sizeBefore != newMap.length) value = newMap;
return result;
}, 'put if absent in map');
}