input: Write a function to generate a random number between 0 and 9 that is divisible by 3. If the generated number is not divisible by 3, the function should keep generating new numbers until it finds a valid number. The function should return the valid number.
  assert generate_random_divisible_number() in [0, 3, 6, 9]
  assert generate_random_divisible_number() in [0, 3, 6, 9]
output: import random
  
  def generate_random_divisible_number():
      while True:
          num = random.randint(0, 9)
          if num % 3 == 0:
              return num