如何引用在__init__中创建的tkinter元素

import tkinter as tk

class MyApp:
    def __init__(self):
        self.root = tk.Tk()
        self.label = tk.Label(self.root, text="Hello, World!")
        self.button = tk.Button(self.root, text="Click Me", command=self.button_click)
        
    def button_click(self):
        self.label.config(text="Button Clicked!")
        
    def run(self):
        self.label.pack()
        self.button.pack()
        self.root.mainloop()

app = MyApp()
app.run()