input: Write a function to generate a random number between 0 and 9. The function should accept no parameters and return the generated random number.
  assert generate_random_number() in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
  assert generate_random_number() in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
  assert generate_random_number() in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
  assert generate_random_number() in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
  assert generate_random_number() in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
output: import random
  
  def generate_random_number():
      return random.randint(0, 9)