Example of AsyncCache for preventing concurrent execution.

main.dart

import 'package:async/async.dart';

/// Example of how AsyncCache can prevent concurrent execution.
void main() async {
  // Call _execute every second.
  // In a real use case, multiple triggers can call [_execute]
  // e.g: start up, user interaction, connectivity change, etc
  for (int i = 0; i < 10; i++) {
    _execute(i);
    await Future.delayed(Duration(seconds: 1));
  }
}

final _cache = AsyncCache.ephemeral();

Future<void> _execute(int index) async {
  print('Attempt: $index');
  
  /// Execution takes 3 seconds
  _cache.fetch(() async {
    print('Executing: $index');
    await Future.delayed(Duration(seconds: 3));
  });
}