How to draw on a sizer?

[Igor Korot]

Hi, ALL,
AFAIK sizers are not windows, and, therefore it shouldn't be
possible to obtain a dc for them.
There is one exception though: wxStaticBoxSizer, which has a
wxStaticBox window.

So, am I correct in the assumption: in order to draw something
on a wxStaticBoxSizer, I need a dc of wxStaticBox?

Thank you.