How to disable after on last element in sass?

Question

css

there is a code

.how
        display: table-cell
        position: relative
        &:after
            content: url(../img/howsArrow.png)
            position: absolute
            top: 32px
            left: 189px

please tell me how to make last-child for after in sass,
this option is not suitable(

.how
        display: table-cell
        position: relative
        &:after
            content: url(../img/howsArrow.png)
            position: absolute
            top: 32px
            left: 189px
            &:last-child:after
                    content: ' '

Answer 1

https://jsfiddle.net/4Lupq9ks/