input: Write a python function to create and pack a button widget in a tkinter window.
  assert isinstance(create_button_widget(tk.Tk(), "Click Me", lambda: print("Button Clicked")), tk.Button)
  assert create_button_widget(tk.Tk(), "Submit", lambda: print("Submitted")).cget("text") == "Submit"
  assert callable(create_button_widget(tk.Tk(), "Run", lambda: print("Running")).cget("command"))
output: def create_button_widget(root, text, command):
      import tkinter as tk
      button = tk.Button(root, text=text, command=command)
      button.pack()
      return button