get_wl_surface
Description:
Returns the Wayland `wl_surface` of a `GdkSurface`.
Parameters:
| this | a `GdkSurface` | 
Returns:
| a Wayland `wl_surface` | 
Returns the Wayland `wl_surface` of a `GdkSurface`.
| this | a `GdkSurface` | 
| a Wayland `wl_surface` |