How to add mixins?

[kadnova]

All the styles in my project made with mixins from other svg-spite plugin, that is no longer works with new version of node.
So can I make something like this with your plugin?

@mixin sp__download_hover {
    @extend %sprite;
    background-position: -44px -50px;
    width: 34px;
    height: 34px;
}

[kadnova]

Found out