public object Copy()
            {
                if (GetType() == typeof(PythonDequeCollection))
                {
                    PythonDequeCollection res = new PythonDequeCollection();
                    res.Extend(this.GetEnumerator());
                    return(res);
                }
                else
                {
                    UserType ut = Ops.GetDynamicType(this) as UserType;
                    System.Diagnostics.Debug.Assert(ut != null);

                    return(ut.Call(new object[] { GetEnumerator() }));
                }
            }