refactor classes, add private, minor fixes

1-js/09-classes/01-class-patterns/1-inheritance-error-assign/task.md

@@ -0,0 +1,29 @@
+importance: 5
+
+---
+
+# An error in the inheritance
+
+Find an error in the prototypal inheritance below.
+
+What's wrong? What are consequences going to be?
+
+```js
+function Animal(name) {
+  this.name = name;
+}
+
+Animal.prototype.walk = function() {
+  alert(this.name + ' walks');
+};
+
+function Rabbit(name) {
+  this.name = name;
+}
+
+Rabbit.prototype = Animal.prototype;
+
+Rabbit.prototype.walk = function() {
+  alert(this.name + " bounces!");
+};
+```