Canguro.Model.Section.SectionManager.this C# (CSharp) Метод

        public Catalog<Section> this[string key]
        {
            get
            {
                return (catalogs.ContainsKey(key)) ? catalogs[key] : null;
            }
            set
            {
                if (catalogs.ContainsKey(key))
                    throw new InvalidIndexException();

                catalogs[key] = value;
                value.CatalogChanged += new EventHandler(oneCatalogChanged);
            }
        }