input: Write a python function to print even numbers in a given range.
  assert printEvenNumbers(1, 10) == "2 4 6 8 10"
  assert printEvenNumbers(4, 20) == "4 6 8 10 12 14 16 18 20"
  assert printEvenNumbers(11, 18) == "12 14 16 18"
output: def printEvenNumbers(start, end):
      return ' '.join(str(i) for i in range(start, end + 1) if i % 2 == 0)