input: Write a python function to generate a list of squares for numbers from 0 to 9.
  assert generate_squares() == [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
  assert generate_squares() != [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]
output: def generate_squares():
      return [i * i for i in range(10)]