code: function fill(toElement, templateElement) {
      var templateContentClone = templateElement.content.cloneNode(true)
      var slot
      var i
  
      if (toElement.childNodes.length) {
        slot = templateContentClone.querySelector('slot')
  
        if (slot) {
          while (toElement.childNodes.length) {
            slot.appendChild(toElement.firstChild)
          }
        }
      }
  
      toElement.appendChild(templateContentClone)
    }
docs: Attach a template's content to an element.
  @public
  @memberof module:simpleComponent
  @param {HTMLElement} toElement The element to attach the template content to
  @param {HTMLElement} template A template element that has the markup guts for the custom element.
  @return {void}