/// <summary>
        /// Gets all items that need to be removed for an item (dependencies+item itself)
        /// </summary>
        public IEnumerable<InstallationItemFactory> GetRemovedFor(InstallationItemFactory i)
        {
            return current.ToList().Where(p => p.Dependencies.Contains(i)).SelectMany(GetRemovedFor).Concat(new[] { i }).ToList();
        }

        /// <summary>
        ///  Gets a sequence of the item itself and its dependencies
        /// </summary>
        public IEnumerable<InstallationItemFactory> GetAddedFor(InstallationItemFactory i)
        {
            return i.Dependencies.SelectMany(GetAddedFor).Concat(new[] { i }).ToList();
        }

vs
        public IEnumerable<InstallationItemFactory> GetItemAndDependenciesForAdding(InstallationItemFactory i)
        {
            return i.Dependencies.SelectMany(GetItemAndDependencies).Concat(new[] { i }).ToList();
        }