How to add new rows in WC sales report email

I am working with WC sales report email plugin and trying to add new rows in report email.

Currently it is showing 5 rows as :
1- Total Sign Ups
2- Total Orders
3- Total Items
4- Sales in this period
5- Top Sellers

Now i want to add new 2 fields:

1- Total Shipping for the specified period
2- Net Sales in the specified period

I have created the two new templates same as the other rows and add the code for shipping row as follows:

class WC_SRE_Row_Total_Sales extends WC_SRE_Report_Row {

	/**
	 * The constructor
	 *
	 * @param $date_range
	 *
	 * @access public
	 * @since  1.0.0
	 */
	public function __construct( $date_range ) {
		parent::__construct( $date_range, 'total_shipping', __( 'Shipping in this period', 'woocommerce-sales-report-email' ) );
	}

	/**
	 * Prepare the data
	 *
	 * @access public
	 * @since  1.0.0
	 */
	public function prepare() {

		// Create a Report Manager object
		$report_manager = new WC_SRE_Report_Manager( $this->get_date_range() );

		// Get the total sales
		$total_shipping = $report_manager->get_order_report_data( array(
			'data'         => array(
				'_order_total' => array(
					'type'     => 'meta',
					'function' => 'SUM',
					'name'     => 'total_shipping'
				),
			),
			'query_type'   => 'get_var',
			'filter_range' => true
		) );

		// Set the value
        echo $total_shipping. "Test";
		$this->set_value( wc_price( $total_shipping ) );
	}

}

Also i have get this row in the email file as:

// Create the date range object
		$date_range = new WC_SRE_Date_Range( WC_SRE_Options::get_interval() );

		// Add the elements
		$this->rows = array(
			new WC_SRE_Row_Total_Sign_Ups( $date_range ),
			new WC_SRE_Row_Total_Orders( $date_range ),
			new WC_SRE_Row_Total_Items( $date_range ),
			new WC_SRE_Row_Total_Sales( $date_range ),
			new WC_SRE_Row_Top_Sellers( $date_range ),
            new WC_SRE_Row_Gross_Sales( $date_range ),
            new WC_SRE_Row_Total_Shipping( $date_range ),
            new WC_SRE_Row_Net_Sales( $date_range ),
		);

Now i want to know is it good approach it will work or not