QgsProcessingGuiRegistry 返回错误的 QgsAbstractProcessingParameterWidgetWrapper 类

The following code defines a CustomStringParameterWidgetWrapper. A CustomStringParameterWidgetFactory is registered to the QgsGui.processingGuiRegistry(). test_widget_wrapper_creation tries to create a CustomStringParameterWidgetWrapper instance from (a) the factory (works) and (b) the QgsGui.processingGuiRegistry(), which fails.