newsupernova/dev/tests/integration/testsuite/Magento/Checkout/_files/customers.php

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */

use Magento\Customer\Model\CustomerRegistry;

$objectManager = \Magento\TestFramework\Helper\Bootstrap::getObjectManager();
$repository = $objectManager->create(\Magento\Customer\Api\CustomerRepositoryInterface::class);
$customer = $objectManager->create(\Magento\Customer\Model\Customer::class);
$customerRegistry = $objectManager->get(CustomerRegistry::class);
$customer->setWebsiteId(1)
    ->setId(1)
    ->setEmail('customer1@example.com')
    ->setPassword('password')
    ->setGroupId(1)
    ->setStoreId(1)
    ->setIsActive(1)
    ->setFirstname('John')
    ->setLastname('Smith')
    ->setDefaultBilling(1)
    ->setDefaultShipping(1);
$customer->isObjectNew(true);
$customer->save();

$customer->setWebsiteId(1)
    ->setId(2)
    ->setEmail('customer2@example.com')
    ->setPassword('password')
    ->setGroupId(1)
    ->setStoreId(1)
    ->setIsActive(1)
    ->setFirstname('Jane')
    ->setLastname('Smith')
    ->setDefaultBilling(1)
    ->setDefaultShipping(1);
$customer->isObjectNew(true);
$customer->save();

$customerRegistry->remove($customer->getId());