How do you disable a 3rd party keyboard in your iOS app

Can you disable 3rd party keyboards in iOS?

If so, how?

Add this method to your UIApplicationDelegate

-(BOOL)application:(UIApplication *)application shouldAllowExtensionPointIdentifier:(NSString *)extensionPointIdentifier
    {

        if (extensionPointIdentifier == UIApplicationKeyboardExtensionPointIdentifier)
        {
            return NO;
        }

        return YES;
    }