remove optional notification arguments from options if None (fixes #2427)

nicegui/elements/notification.py

@@ -62,16 +62,19 @@ class Notification(Element, component='notification.js'):
         self._props['options'] = {
             'message': str(message),
             'position': position,
-            'type': type,
-            'color': color,
             'multiLine': multi_line,
-            'icon': icon,
             'spinner': spinner,
             'closeBtn': close_button,
             'timeout': (timeout or 0) * 1000,
             'group': False,
             'attrs': {'data-id': f'nicegui-dialog-{self.id}'},
         }
+        if type is not None:
+            self._props['options']['type'] = type
+        if color is not None:
+            self._props['options']['color'] = color
+        if icon is not None:
+            self._props['options']['icon'] = icon
         self._props['options'].update(kwargs)
         with self:
             def delete():
@@ -108,21 +111,27 @@ class Notification(Element, component='notification.js'):
     @property
     def type(self) -> NotificationType:
         """Type of the notification."""
-        return self._props['options']['type']
+        return self._props['options'].get('type')
 
     @type.setter
     def type(self, value: NotificationType) -> None:
-        self._props['options']['type'] = value
+        if value is None:
+            self._props['options'].pop('type', None)
+        else:
+            self._props['options']['type'] = value
         self.update()
 
     @property
     def color(self) -> Optional[str]:
         """Color of the notification."""
-        return self._props['options']['color']
+        return self._props['options'].get('color')
 
     @color.setter
     def color(self, value: Optional[str]) -> None:
-        self._props['options']['color'] = value
+        if value is None:
+            self._props['options'].pop('color', None)
+        else:
+            self._props['options']['color'] = value
         self.update()
 
     @property
@@ -138,11 +147,14 @@ class Notification(Element, component='notification.js'):
     @property
     def icon(self) -> Optional[str]:
         """Icon of the notification."""
-        return self._props['options']['icon']
+        return self._props['options'].get('icon')
 
     @icon.setter
     def icon(self, value: Optional[str]) -> None:
-        self._props['options']['icon'] = value
+        if value is None:
+            self._props['options'].pop('icon', None)
+        else:
+            self._props['options']['icon'] = value
         self.update()
 
     @property