input: Write a function to iterate over a list of numbers and print only the even numbers. Provide the function with a sample input list and ensure it prints the correct output.
  assert print_even_numbers([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])==None
  Output should be:
  2
  4
  6
  8
  10
output: def print_even_numbers(numbers):
      for num in numbers:
          if num % 2 == 0:
              print(num)