System.Xml.Serialization.SchemaObjectCache.AddItem C# (CSharp) Method

        internal XmlSchemaObject AddItem(XmlSchemaObject item, XmlQualifiedName qname, XmlSchemas schemas) {
            if (item == null)
                return null;
            if (qname == null || qname.IsEmpty) 
                return null;

            string key = item.GetType().Name + ":" + qname.ToString();
            ArrayList list = (ArrayList)ObjectCache[key];
            if (list == null) {
                list = new ArrayList();
                ObjectCache[key] = list;
            }

            for (int i = 0; i < list.Count; i++) {
                XmlSchemaObject cachedItem = (XmlSchemaObject)list[i];
                if (cachedItem == item)
                    return cachedItem;

                if (Match(cachedItem, item, true)) {
                    return cachedItem;
                }
                else {
                    Warnings.Add(Res.GetString(Res.XmlMismatchSchemaObjects, item.GetType().Name, qname.Name, qname.Namespace));
                    Warnings.Add("DEBUG:Cached item key:\r\n" + (string)looks[cachedItem] + "\r\nnew item key:\r\n" + (string)looks[item]);
                }
            }
            // no match found we need to insert the new type in the cache
            list.Add(item);
            return item;
        }