Creating sub classes with prototype assigning directly will confuse instanceof operator.

wrong_sub_class.js

var util = require('util')


function Class() {}
function SubClass() {}
function WrongSubClass() {}

util.inherits(SubClass, Class)
util.inherits(WrongSubClass, Class)

WrongSubClass.prototype = Class.prototype

var foo = new SubClass()

console.log(foo instanceof WrongSubClass) // ==> logs true, should be false obviously