input: Write a function to create a tkinter window with specified dimensions.
  assert create_window(200, 200) == (200, 200)
  assert create_window(300, 300) == (300, 300)
  assert create_window(400, 400) == (400, 400)
output: def create_window(width, height):
      import tkinter as tk
      root = tk.Tk()
      root.geometry(f"{width}x{height}")
      current_width = root.winfo_width()
      current_height = root.winfo_height()
      root.destroy()
      return (current_width, current_height)