input: Write a function to generate a random number between 0 and 9. The function should return the generated number.
  def generate_random_number():
      import random
      return random.randint(0, 9)
  assert generate_random_number() <= 9
  assert generate_random_number() >= 0
output: def generate_random_number():
      import random
      return random.randint(0, 9)