{% macro render(heading, options = {}) %} {% set classes = ['PaperStackItem'] %} {% set classes = (classes.push('PaperStackItem--isDraggable') if options.draggable, classes) %} {% set classes = (classes.push('PaperStackItem--item' + options.index) if options.index, classes) %} {% set classes = (classes.push(options.classes | join(' ')) if options.classes, classes) %} {% set classes = classes | join(' ') | trim %} {% set tabIndex = 'tabindex="1"' if options.draggable %}