func TestUnevenStep(t *testing.T) {
	r := ranging.FromToStep(0, 5, 2)

	for i := 0; i < 5; i += 2 {
		v := <-r
		if i != int(v) {
			t.Errorf("Expected: %d Got: %d", i, v)
		}
	}
}
func TestUnevenNegativeStep(t *testing.T) {
	r := ranging.FromToStep(100, -113, -20)

	for i := 100; i > -100; i -= 20 {
		v := <-r
		if i != int(v) {
			t.Errorf("Expected: %d Got: %d", i, v)
		}
	}
}
func ExampleFromToStep() {
	for i := range ranging.FromToStep(5, -5, -2) {
		fmt.Println(i)
	}
	//Output: 5
	//3
	//1
	//-1
	//-3
}