underrscore.js学习系列
https://blog.csdn.net/liangrongliu1991/article/details/78909472
https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Inheritance_and_the_prototype_chain
https://github.com/KenNaNa/underrscore.js-/blob/master/8-underscore.js_isNumberic.html
https://github.com/KenNaNa/underrscore.js-/blob/master/9-underscore.js_isObject.html
https://github.com/KenNaNa/underrscore.js-/blob/master/10-underscore.js_isSymbol.html
https://github.com/KenNaNa/underrscore.js-/blob/master/11-underscore.js_isFinite.html
https://github.com/KenNaNa/underrscore.js-/blob/master/14-underscore.js_isNull.html
https://github.com/KenNaNa/underrscore.js-/blob/master/15-underscore.js_isUndefined.html
https://github.com/KenNaNa/underrscore.js-/blob/master/16-underscore.js_random.html
https://github.com/KenNaNa/underrscore.js-/blob/master/17-underscore.js_now.html
https://github.com/KenNaNa/underrscore.js-/blob/master/18-underscore.js_new.html
https://github.com/KenNaNa/underrscore.js-/blob/master/19-underscore.js_inheritsObj.html
https://github.com/KenNaNa/underrscore.js-/blob/master/12-underscore.js_isNaN.html