WordPress at a glance
function is not described

Automattic\WooCommerce\Admin\Overrides

OrderRefund::get_report_customer_id() public WC 1.0

Get the customer ID of the parent order used for reports in the customer lookup table.

{} It's a method of the class: OrderRefund{}

No Hooks.

Return

Int|true|false. Customer ID of parent order, or false if parent order not found.

Usage

$OrderRefund = new OrderRefund();
$OrderRefund->get_report_customer_id();

Code of OrderRefund::get_report_customer_id() WC 5.3.0

<?php
public function get_report_customer_id() {
	$parent_order = wc_get_order( $this->get_parent_id() );

	if ( ! $parent_order ) {
		return false;
	}

	return CustomersDataStore::get_or_create_customer_from_order( $parent_order );
}