* get the prefixed property * @param {Object} obj * @param {String} property * @returns {String|Undefined} prefixed

* removeEventListener with multiple events at once * @param {EventTarget} target * @param {String} types * @param {Function} handler

* set a timeout with a given scope * @param {Function} fn * @param {Number} timeout * @param {Object} context * @returns {number}

* (Internal) Adds a class to an element.

* simple function bind * @param {Function} fn * @param {Object} context * @returns {Function}

* direction cons to string * @param {Const} direction * @returns {String}

* get the center of all the pointers * @param {Array} pointers * @return {Object} center contains `x` and `y` properties

* get the direction between two points * @param {Number} x * @param {Number} y * @return {Number} direction

组装返回给前台的消息 @param message 交互信息 @param type 信息类型 @param list 在线列表 @return

* 获取字符串的utf8编码字节串 * @param {string} string * @return {array}

* get the window object of an element * @param {HTMLElement} element * @returns {DocumentView|Window}

* (Internal) Determines if an element or space separated list of class names contains a class name.

* find if a node is in the given parent * @method hasParent * @param {HTMLElement} node * @param {HTMLElement} parent * @return {Boolean} foun

* use the val2 when val1 is undefined * @param {*} val1 * @param {*} val2 * @returns {*}

* merge the values from src in the dest. * means that properties that exist in dest will not be overwritten by src * @param {Object} dest * @par