input: Write a function to generate a random number between 0 and 9. The function should return the generated random number.
  
  def generate_random_number():
      return random.randint(0, 9)
  
  assert generate_random_number() in range(10)
  assert isinstance(generate_random_number(), int)
output: def generate_random_number():
      return random.randint(0, 9)