AttachToOrGet from entity framework context

AttachToOrGet

public static void AttachToOrGet<T>(this ObjectContext context, string entitySetName, ref T entity)
	where T : IEntityWithKey
{
	ObjectStateEntry entry;
	// Track whether we need to perform an attach
	bool attach = false;
	if (
		context.ObjectStateManager.TryGetObjectStateEntry
			(
				context.CreateEntityKey(entitySetName, entity),
				out entry
			)
		)
	{
		// Re-attach if necessary
		attach = entry.State == EntityState.Detached;
		// Get the discovered entity to the ref
		entity = (T)entry.Entity;
	}
	else
	{
		// Attach for the first time
		attach = true;
	}
	if (attach)
		context.AttachTo(entitySetName, entity);
}