libhal_ctx_set_user_data (priv->hal, plugin);
libhal_ctx_set_device_property_modified (priv->hal,
flashlight_status_plugin_on_hal_property_modified);
libhal_ctx_set_user_data (priv->hal, plugin);
libhal_ctx_set_device_property_modified (priv->hal,
flashlight_status_plugin_on_hal_property_modified);