input: Write a python function to extract even integers from a given list.
  assert ExtractEvens([1,2,3,4,5]) == [2,4]
  assert ExtractEvens([4,5,6,7,8,0,1]) == [4,6,8,0]
  assert ExtractEvens([8,12,15,19]) == [8,12]
output: def ExtractEvens(lst):
      return [x for x in lst if x % 2 == 0]