IronRuby.Hpricot.DocumentType.GetSystemId C# (CSharp) Method

        public static Object GetSystemId(DocumentType/*!*/ self)
        {
            var data = self.GetData<AttributeData>();
            if (data.AttrIsEmpty) {
                return null;
            }
            Object value;
            data.AttrAsHash.TryGetValue(self._systemId, out value);
            return value;
        }