Yii2 carnt access Mailchimp_Lists class using mailchimp wrapper

I am using the yii2-mailchimp extension which can be found here (Sammaye/yii2-mailchimp)

I am wanting to subscribe a user however am unable to access the Mailchimp_Lists class as I need to use the subscribe function within it.

Below is my setup


<?php 


namespace frontend\controllers;


use sammaye\mailchimp\Mailchimp;

use frontend\models\Newsletter;

use yii\helpers\Html;

use yii\base\InvalidParamException;

use yii\web\BadRequestHttpException;

use yii\web\Controller;

use yii\filters\VerbFilter;

use yii\filters\AccessControl;

use Yii;




class NewsletterController extends Controller{

    public function actionNewslettersignup()

    {


        $model = new Newsletter();


        // Using isset will make sure, you don't trigger a Notice (when the variable does not exist)

        $email = isset($_POST['Newsletter']['email']) ? $_POST['Newsletter']['email'] : null;


        // Make sure you are receiving an email address

        if ($email && filter_var($email, FILTER_VALIDATE_EMAIL))

        {

            // Subscribe User to List

            $api_key = "xxxxxxxxxxxx";

            $list_id = "xxxxxx";


            $mc = new Mailchimp(['apikey' => $api_key]);

            $Mailchimp_Lists = new Mailchimp_Lists( $mc );


            //just to test what was being outputted

            var_dump($mc->lists->getList());


            echo $api_key;

            echo $list_id;

        }

        // Display an error message ?

        else 

        {

            // @todo

        }


    }

}

I have managed to get it working to an extent however i get the following error


Missing argument 2 for Mailchimp_Lists::subscribe()

Here is my new setup


<?php 


namespace frontend\controllers;


use sammaye\mailchimp\Mailchimp;

use frontend\models\Newsletter;

use yii\helpers\Html;

use yii\base\InvalidParamException;

use yii\web\BadRequestHttpException;

use yii\web\Controller;

use yii\filters\VerbFilter;

use yii\filters\AccessControl;

use Yii;




class NewsletterController extends Controller{

	public function actionNewslettersignup()

    {


        $model = new Newsletter();


		// Using isset will make sure, you don't trigger a Notice (when the variable does not exist)

		$email = isset($_POST['Newsletter']['email']) ? $_POST['Newsletter']['email'] : null;


		$merge_vars = array('email' => $_POST['Newsletter']['email'], 'FNAME' => $_POST['Newsletter']['fname'], 'LNAME' => $_POST['Newsletter']['lname']);


		// Make sure you are receiving an email address

		if ($email && filter_var($email, FILTER_VALIDATE_EMAIL))

		{

		    // Subscribe User to List

		    $api_key = "xxxxxxxxx";

		    $list_id = "xxxxxx";


		    $mc = new Mailchimp(['apikey' => $api_key]);


		    


		    $result = $mc->lists->subscribe(array(

            'id'                => $list_id,

            'email'             => array('email'=>$email),

            'merge_vars'        => $merge_vars,

            'double_optin'      => false,

            'update_existing'   => true,

            'replace_interests' => false,

            'send_welcome'      => false,

        	));


    		print_r($result);


		    echo $api_key;

		    echo $list_id;

		}

		// Display an error message ?

		else 

		{

		    // @todo

		}


    }

}