closes issue #166

Author: AMISH-KHAN

courses/react-js/advanced-level/component-optimization/MemoizationExample.js

@@ -1,10 +1,16 @@
 import React, { useMemo, useState } from "react";
+import PropTypes from 'prop-types';
+
 
 const ExpensiveComponent = ({ value }) => {
   const expensiveFunction = (value) => {
     // Expensive computation
     return value * 2;
   };
+  
+  ExpensiveComponent.propTypes = {
+    value: PropTypes.number.isRequired
+  };
   const memoizedValue = useMemo(() => expensiveFunction(value), [value]);
   return <div>{memoizedValue}</div>;
 };