code: function (el, att) {
    var result = false
    if (/^\.[\w]+/.test(att)) {
      var className = att.match(/^\.([\w]+)/)[1]
      var gClass = el.className.split(' ')
      if (gClass.indexOf(className)>-1) {
        result = true
      }
    }
    if (/^\#[\w]+/.test(att)) {
      var idName = att.match(/^\#([\w]+)/)[1]
      if (el.hasAttribute('id') && el.getAttribute('id')===idName) result = true
    }
    if (/^\[[\w]+=\"[\w]+\"\]$/.test(att)) {
      var attr = att.match(/^\[([\w]+)=\"([\w]+)\"\]$/)
      var attName = attr[1]
      var attval = attr[2]
      if (el.hasAttribute(attName) && el.getAttribute(attName)===attval) result = true
    }
    if (/^\[[\w]+=\'[\w]+\'\]$/.test(att)){
      var attr = att.match(/^\[([\w]+)=\'([\w]+)\'\]$/)
      var attName = attr[1]
      var attval = attr[2]
      if (el.hasAttribute(attName) && el.getAttribute(attName)===attval) result = true
    }
    return result
  }
docs: (el → dom, att → string)
  return boolen
  - check if has attribute