如何在执行后清除文本字段？KivyMD

from kivymd.app import MDApp
from kivymd.uix.textfield import MDTextField
from kivy.uix.boxlayout import BoxLayout

class ClearTextFieldApp(MDApp):
    def build(self):
        layout = BoxLayout(orientation='vertical')
        text_field = MDTextField()
        layout.add_widget(text_field)
        return layout

    def clear_text_field(self, instance):
        instance.text = ''

if __name__ == '__main__':
    ClearTextFieldApp().run()