Implemented "CloseNotification" function

src/main.vala

@@ -122,7 +122,7 @@ namespace SwayNotificatonCenter {
         }
 
         public void CloseNotification (uint32 id) throws DBusError, IOError {
-            print ("yeet");
+            notiWin.close_notification (id);
         }
 
         public void GetServerInformation (out string name,

src/notiWindow/notiWindow.vala

@@ -12,10 +12,16 @@ namespace SwayNotificatonCenter {
             GtkLayerShell.set_anchor (this, GtkLayerShell.Edge.RIGHT, true);
         }
 
+        private void removeWidget (Gtk.Widget widget) {
+            uint len = box.get_children ().length () - 1;
+            box.remove (widget);
+            if (len <= 0) box.set_visible (false);
+        }
+
         public void replace_notification (NotifyParams param) {
             foreach (var w in box.get_children ()) {
                 if (((Notification) w).param.applied_id == param.replaces_id) {
-                    box.remove (w);
+                    removeWidget (w);
                     break;
                 }
             }
@@ -31,5 +37,14 @@ namespace SwayNotificatonCenter {
             });
             this.show_all ();
         }
+
+        public void close_notification (uint32 id) {
+            foreach (var w in box.get_children ()) {
+                if (((Notification) w).param.applied_id == id) {
+                    removeWidget (w);
+                    break;
+                }
+            }
+        }
     }
 }