using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace ProjectNamespace.Code { public class FileList : Dictionary<string, List<string>> { new public List<string> this[string key] { get { if (!ContainsKey(key)) Add(key, new List<string>() { }); return base[key]; } set { base[key] = value; } } public FileList Concat(string name, string fileName) { this[name].Add(fileName); return this; } } }