input: Write a function to get even numbers from a list.
  assert get_even_numbers([1, 2, 3, 4, 5, 6]) == [2, 4, 6]
  assert get_even_numbers([10, 15, 20, 25, 30]) == [10, 20, 30]
  assert get_even_numbers([7, 8, 10, 13, 14]) == [8, 10, 14]
output: def get_even_numbers(numbers):
      return [num for num in numbers if num % 2 == 0]