Boo.Lang.Compiler.TypeSystem.TypeSystemServices.GetExternalEnumeratorItemType C# (CSharp) Method

        private IType GetExternalEnumeratorItemType(IType iteratorType)
        {
            Type type = ((ExternalType) iteratorType).ActualType;
            var attribute = (EnumeratorItemTypeAttribute) Attribute.GetCustomAttribute(type, typeof(EnumeratorItemTypeAttribute));
            return null != attribute ? Map(attribute.ItemType) : null;
        }