public function init_gateways() {
	load_plugin_textdomain( 'wpjobster-sample', false, 
					trailingslashit( dirname( plugin_basename( __FILE__ ) ) ) );
	add_filter( 'wpjobster_payment_gateways', array( $this, 'add_gateways' ) );
}

This function will merge the gateway that we are building with the other gateways.