input: Write a function to generate a list of 3 unique random numbers between 0 and 9.
  assert len(generate_random_numbers())==3
  assert all(0 <= num < 10 for num in generate_random_numbers())
  assert len(set(generate_random_numbers()))==3
output: import random
  
  def generate_random_numbers():
      return random.sample(range(10), 3)