public async Task GIVEN_changed_aggregate_root_WHEN_attempting_to_save_THEN_saves_aggregate_root(string serializedAggregateRootId)
{
// Arrange
var repository = new TestRepository(_mockFactory.Object, _mockEventStore.Object);
var aggregateRootId = new TestAggregateRootId(serializedAggregateRootId);
var aggregateRoot = new TestAggregateRoot(aggregateRootId);
aggregateRoot.ExecuteBehavior();
// Act
await repository.SaveAsync(aggregateRoot);
// Assert
_mockEventStore.Verify(m => m.SaveAsync(It.IsAny <IReadOnlyCollection <Event> >(), It.IsAny <string>(), It.IsAny <CancellationToken>()), Times.Once());
}