input: Write a python function to sum even numbers in a list.
  assert sum_even_numbers([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) == 30
  assert sum_even_numbers([10, 21, 32, 43, 54, 65]) == 96
  assert sum_even_numbers([11, 13, 15, 17, 19]) == 0
output: def sum_even_numbers(numbers):
      return sum(number for number in numbers if number % 2 == 0)