vue-simple-range-slider/src/vue2/node_modules/css-tree/lib/syntax/function/expression.js

Change Your numeric value or numeric range value with dragging handles

// legacy IE function
// expression( <any-value> )
module.exports = function() {
    return this.createSingleNodeList(
        this.Raw(this.scanner.tokenIndex, null, false)
    );
};