Sets whether @widget is included in the measured size of @overlay.
The overlay will request the size of the largest child that has
this property set to %TRUE. Children who are not included may
be drawn outside of @overlay's allocation if they are too large.
Sets whether @widget is included in the measured size of @overlay.
The overlay will request the size of the largest child that has this property set to %TRUE. Children who are not included may be drawn outside of @overlay's allocation if they are too large.