input: Write a python function to generate a list of 20 random numbers between 1 and 10.
  assert len(generate_random_numbers()) == 20
  assert all(1 <= num <= 10 for num in generate_random_numbers())
  assert len(set(generate_random_numbers())) > 1
output: import random
  
  def generate_random_numbers():
      return [random.randint(1, 10) for _ in range(20)]