Kivy Python的动画错误？

Question

我正在尝试动画应用。它显示了一个错误代码，表示构建需要两个参数（给定1个）。这是我的代码：

from kivy.app import App 
from kivy.uix.image import Image 
from kivy.animation import Animation 

class TheApp(App): 

    def build(self, instance):
        self.instance= instance
        image = Image(source= "psychTREE.jpg")
        image.allow_stretch= True

        animation = Animation(pos= (100, 100), t= "out_bounce") 
        animation += Animation(pos= (200, 100), t = "out_bounce") 
        animation &= Animation(size= (500, 500))
        animation += Animation(size= (100, 50)) 

        image = animation.start(instance)  
        return image 

if __name__ == "__main__":
    TheApp().run()