This is very similar to using an Application subclass and overriding the attachBaseContext() method.

However, using this method, you don’t need to override attachBaseContext() as this is already done in the MultiDexApplication superclass.

Extend MultiDexApplication instead of Application:

package com.example;

import android.support.multidex.MultiDexApplication;
import android.content.Context;

/**
 * Extended MultiDexApplication 
 */
public class MyApplication extends MultiDexApplication {

     // No need to override attachBaseContext()

     //..........
}

Add this class to your AndroidManifest.xml exactly as if you were extending Application:

<application
    android:name="com.example.MyApplication"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name">
</application>