code: static int[] toIntArray(List<Integer> integers) {
  		int[] ints = new int[integers.size()];
  		int i = 0;
  		for (Integer n : integers) {
  			ints[i++] = n;
  		}
  		return ints;
  	}
docs: Transforms a list of Integer objects to an array of primitive int values.
  
  @param integers
  @return