code: function moveChildTag(tag, tagName, newPos) {
    var parent = tag.parent,
      tags
    // no parent no move
    if (!parent) return
  
    tags = parent.tags[tagName]
  
    if (isArray(tags))
      tags.splice(newPos, 0, tags.splice(tags.indexOf(tag), 1)[0])
    else addChildTag(tag, tagName, parent)
  }
docs: Move the position of a custom tag in its parent tag
  @param   { Object } tag - child tag instance
  @param   { String } tagName - key where the tag was stored
  @param   { Number } newPos - index where the new tag will be stored