Is there a way to restrict the rendering of a `WMSLayer` to a specified extent without restricting map panning and zooming? That is, I need the client to be able to pan outside the limits of the `WMSLayer`, in which case only the basemap should be displayed.

The WMS Server is external and outside of my control.

One idea would be to use a server proxy to receive the WMS request and forward it to the WMS server only if the `BBOX` is valid, but I would rather find a client-side solution.