4. Write a function that takes a list of integers and moves all even elements to the front of the list, otherwise preserving the order of the elements. The function should return a new list. Name the function evens (values). For example, evens ([ 1 , 4 , 9 , 16 , 25 ] ) should return [ 4 , 16 , 1 , 9 , 25 ] ..