Magento 1.9 Observer - How do visible selected payment gateway only for specific customer group?

Question

Following code return customer group, how to add condition if customer group "Tester" then only show selected payment gateway?

app\etc\modules\Gta_FindPaymentGateway.xml

<?xml version="1.0"?>
<config>
    <modules>
        <Gta_FindPaymentGateway>
            <codePool>local</codePool>
            <active>true</active>
        </Gta_FindPaymentGateway>
    </modules>
</config>

app\code\local\Gta\FindPaymentGateway\etc\config.xml

<?xml version="1.0"?>
<config>
    <modules>
        <Gta_FindPaymentGateway>
            <version>1.0.0</version>
        </Gta_FindPaymentGateway>
    </modules>
    <global> 
        <models>
            <gta_findpaymentgateway>
                <class>Gta_FindPaymentGateway_Model</class>
            </gta_findpaymentgateway>
        </models> 
        <events>
            <checkout_cart_product_add_after>
                <observers>
                    <Gta_FindPaymentGateway_Model_Observer>   
                        <type>singleton</type>
                        <class>Gta_FindPaymentGateway_Model_Observer</class>
                        <method>paymenter</method>
                    </Gta_FindPaymentGateway_Model_Observer>
                </observers>
            </checkout_cart_product_add_after>      
        </events>
    </global> 
</config>

app\code\local\Gta\FindPaymentGateway\Model\Observer.php

<?php
    class Gta_FindPaymentGateway_Model_Observer
    {
        public function paymenter($Observer)
        {
            if(Mage::getSingleton('customer/session')->isLoggedIn())
            {
                // Get group Id
                $groupId = Mage::getSingleton('customer/session')->getCustomerGroupId();

                //Get customer Group name
                $group = Mage::getModel('customer/group')->load($groupId);

                 Mage::log($group->getCode(),null,'filter.log',true);
            }
        }
    }
?>