Dev2.Studio.Deploy.DeployStatsCalculator.CheckForNamingConflicts C# (CSharp) Method

        public IEnumerable<IExplorerItemModel> CheckForNamingConflicts(List<IExplorerItemModel> items,  DeployNavigationViewModel targetNavViewModel)
        {
            var vm = items;
            if (vm == null || !vm.All(a => a.IsChecked.GetValueOrDefault(false))) return  new List<IExplorerItemModel>();
            if (targetNavViewModel != null && targetNavViewModel.Environment != null)
            {
                IEnvironmentModel targetEnvironment = targetNavViewModel.Environment;
                if (targetEnvironment == null || targetEnvironment.ResourceRepository == null) return new List<IExplorerItemModel>();

                var all = targetEnvironment.ResourceRepository.All();
                if(all != null)
                {
                    var conflictingItems = all.Join(vm, a => a.Category, explorerItemModel => explorerItemModel.ResourcePath, (a, explorerItemModel) => new { a, explorerItemModel }).Where(@t => @t.explorerItemModel.ResourceId != @t.a.ID).Select(@t => @t.explorerItemModel);


                    return conflictingItems;
                }
            }
            return new List<IExplorerItemModel>();
        }
    }