input: Write a python function to draw a star using the turtle module.
  assert draw_star() == "Star drawn"
output: def draw_star():
      import turtle
  
      # Set up the screen
      screen = turtle.Screen()
      screen.bgcolor("white")
  
      # Create a turtle
      star_turtle = turtle.Turtle()
      star_turtle.color("black")
      star_turtle.speed(3)  # Set the speed of the turtle
  
      # Function to draw a star
      def star(turtle, size):
          if size <= 10:  # Base case
              return
  
          for i in range(5):
              turtle.forward(size)
              star(turtle, size / 3)  # Recursive call
              turtle.right(144)
  
      # Draw the star
      star(star_turtle, 100)
  
      # Hide the turtle and display the window
      star_turtle.hideturtle()
      screen.mainloop()
  
      return "Star drawn"