Minor cleanup

gtk/src/toga_gtk/window.py

@@ -243,10 +243,9 @@ def set_window_state(self, state):
             elif current_state == WindowState.PRESENTATION:
                 if isinstance(self.native, Gtk.ApplicationWindow):
                     self.native.set_show_menubar(True)
-                if self.native_toolbar:
-                    self.native_toolbar.set_visible(True)
-                else:  # pragma: no cover
-                    pass
+                # self.native_toolbar is always set to Gtk.Toolbar(), so no need
+                # to check if self.native_toolbar exists.
+                self.native_toolbar.set_visible(True)
                 self.native.unfullscreen()
 
                 self.interface.screen = self._before_presentation_mode_screen
@@ -270,10 +269,9 @@ def set_window_state(self, state):
                     self._before_presentation_mode_screen = self.interface.screen
                 if isinstance(self.native, Gtk.ApplicationWindow):
                     self.native.set_show_menubar(False)
-                if self.native_toolbar:
-                    self.native_toolbar.set_visible(False)
-                else:  # pragma: no cover
-                    pass
+                # self.native_toolbar is always set to Gtk.Toolbar(), so no need
+                # to check if self.native_toolbar exists.
+                self.native_toolbar.set_visible(False)
                 self.native.fullscreen()
                 self._is_in_presentation_mode = True
             else:  # pragma: no cover