Use !default for sass variables

[aganov]

Is it possible to update sass variables with default option so it will be easier to overwrite them on application level?

Something like this

$scrollable: asScrollable !default;
$scrollable-bar-size: 4px !default;
$scrollable-bar-dragging-size: 10px !default;
$scrollable-bar-dragging-color: rgba(238, 238, 238, .6) !default;
$scrollable-bar-hovering-color: rgba(238, 238, 238, .4) !default;
$scrollable-bar-handle-offset: 5px !default;
$scrollable-bar-handle-color: rgba(224, 224, 224, .6) !default;
$scrollable-bar-handle-hovering-color: rgba(150, 150, 150, .6) !default;
$scrollable-bar-handle-dragging-color: rgba(150, 150, 150, .8) !default;