cork-class-mixin-builder.html

<script>
 /**
  * From:
  * https://stackoverflow.com/questions/41839198/applying-behaviors-with-js-mixins-in-polymer-2
  * */

  class MixinBuilder {  
    constructor(superclass) {
      this.superclass = superclass;
    }
    with(...mixins) { 
      return mixins.reduce((c, mixin) => mixin(c), this.superclass);
    }
  }
  const Mixin = (superclass) => new MixinBuilder(superclass);
</script>