code: function appendElementSelector (element, selector) {
    const processor = selectorParser((selectors) => {
      let combinatorNode = null
  
      /**
       * looping breaks if we insert dynamically
       */
      selectors.each((selector) => {
        const elementNode = selectorParser.tag({ value: element.tag })
        selector.walk((node) => {
          if (node.type === 'combinator') { combinatorNode = node }
        })
  
        if (combinatorNode) {
          selector.insertAfter(combinatorNode, elementNode)
        } else {
          selector.prepend(elementNode)
        }
      })
    })
  
    return processor.process(selector).result
  }
docs: Add the element tag to the end of the selector
  @param  {Object} element  element definition
  @param  {String} selector the selector
  @return {String}          the modified selector