get_size_request
Description:
Gets the size request that was explicitly set for the widget.
A value of -1 stored in width or height indicates that that dimension has not been set explicitly and the natural 
      requisition of the widget will be used instead.
See [method@Gtk.Widget.set_size_request].
To get the size a widget will actually request, call [method@Gtk.Widget.measure] instead of this function.
Parameters:
| this | a widget | 
| width | return location for width | 
| height | return location for height |