code: def on_clear_button_pressed(self):
          
          self.path = None
          self.clear_button.setEnabled(False)
          self.folder_label.setText(self.initial_folder_label_text)
          logger.debug("User selects to clear the custom module search path.")
docs: PyQt slot called when the user hits the "Clear" button.
          Removes any set custom module search path.