code: function arrayUnion () {
    var args = arguments
    var result = []
    var index = 0
    var len = args.length
    for (; index < len; index++) {
      result = result.concat(toArray(args[index]))
    }
    return arrayUniq(result)
  }
docs: 将多个数的值返回唯一的并集数组
  
  @param {...Array} 数组
  @return {Array}