如何在Kivy中通过单击一个按钮更改另一个按钮(按钮)的文本？

from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.boxlayout import BoxLayout

class MyBoxLayout(BoxLayout):
    def __init__(self, **kwargs):
        super(MyBoxLayout, self).__init__(**kwargs)
        
        # 创建两个按钮
        self.button1 = Button(text="按钮1", on_press=self.change_button_text)
        self.button2 = Button(text="按钮2")
        
        # 将按钮添加到布局中
        self.add_widget(self.button1)
        self.add_widget(self.button2)

    def change_button_text(self, instance):
        self.button2.text = "按钮2的文本已更改"

class MyApp(App):
    def build(self):
        return MyBoxLayout()

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