input: Write a function to generate a random number between 0 and 9. The function should return the generated number.
  assert generate_random_number()==5
  assert generate_random_number()==2
  assert generate_random_number()==7
  import random
  
  def generate_random_number() -> int:
      return random.randint(0, 9)
output: import random
  
  def generate_random_number() -> int:
      return random.randint(0, 9)