class-wc-gateway-paypal-ipn-handler-override.php

<?php

class WC_Gateway_Paypal_IPN_Handler_Override extends WC_Gateway_Paypal_IPN_Handler {

    public function __construct( $sandbox = false, $receiver_email = '' ) {
        add_action( 'valid-paypal-standard-ipn-request', array( $this, 'valid_response' ) );

        $this->receiver_email = $receiver_email;
        $this->sandbox        = $sandbox;
    }

    protected function save_paypal_meta_data( $order, $posted ) {
        // Write your code here
    }
}