begin_resize
Description:
public void begin_resize (SurfaceEdge edge, Device? device, int button, double x, double y, uint32 timestamp)
  
  Begins an interactive resize operation.
You might use this function to implement a “window resize grip.”
Parameters:
| this | a `GdkToplevel` | 
| edge | the edge or corner from which the drag is started | 
| device | the device used for the operation | 
| button | the button being used to drag, or 0 for a keyboard-initiated drag | 
| x | surface X coordinate of mouse click that began the drag | 
| y | surface Y coordinate of mouse click that began the drag | 
| timestamp | timestamp of mouse click that began the drag (use [method@Gdk.Event.get_time]) |