input: Write a python function to sum all even numbers in a given range.
  assert sum_even_in_range(1, 10) == 30
  assert sum_even_in_range(4, 20) == 108
  assert sum_even_in_range(2, 6) == 12
output: def sum_even_in_range(start, end):
      return sum(num for num in range(start, end + 1) if num % 2 == 0)