CollumnEditor in design time

[Guest]

i develop custom control, that is contains Typed Collection derived from CollectionBas

So
in html view my conrol looks like

<cc1:MyControl runat=server id=ctrl1><MyCollection><MyItem Prop=value></MyCollection></cc1:MyControl

so MyItem is NOT Control - it's simply class with one property "Prop

I add attribute [ParseChildren(true)] to MyContro
and it's work correctly.

now i want add designer ability to my control
how i can do it