AvalonStudio.Projects.FileSystemProject.RemoveFiles C# (CSharp) Метод

        private void RemoveFiles(FileSystemProject project, IProjectFolder folder)
        {
            foreach (var item in folder.Items)
            {
                if (item is IProjectFolder)
                {
                    RemoveFiles(project, item as IProjectFolder);
                    project.Folders.Remove(item as IProjectFolder);
                }

                if (item is ISourceFile)
                {
                    project.SourceFiles.Remove(item as ISourceFile);
                }
            }
        }