Implements the calculation of a box sizer's dimensions and then sets
the size of its children (calling \helpref{wxWindow::SetSize}{wxwindowsetsize}
if the child is a window). It is used internally only and must not be called
Implements the calculation of a box sizer's dimensions and then sets
the size of its children (calling \helpref{wxWindow::SetSize}{wxwindowsetsize}
if the child is a window). It is used internally only and must not be called