wc-composable-product/tests/stubs/class-wc-order-item-product.php

<?php
/**
 * Minimal WC_Order_Item_Product stub for unit testing.
 */
class WC_Order_Item_Product extends WC_Data {
    protected $product = null;
    protected $quantity = 1;

    public function get_product() {
        return $this->product;
    }

    public function set_product($product) {
        $this->product = $product;
    }

    public function get_quantity() {
        return $this->quantity;
    }

    public function set_quantity($quantity) {
        $this->quantity = $quantity;
    }

    public function add_meta_data($key, $value, $unique = false) {
        $this->meta_data[$key] = $value;
    }
}