input: Write a python function to print even numbers less than 10 from a given range using step size of 2.
  assert print_even_numbers(range(0, 20, 2))==[0, 2, 4, 6, 8]
  assert print_even_numbers(range(2, 22, 2))==[2, 4, 6, 8]
  assert print_even_numbers(range(1, 21, 2))==[]
output: def print_even_numbers(r):
      return [x for x in r if x < 10 and x % 2 == 0]