magento-test/app/code/Magento/Multishipping/etc/frontend/di.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Framework\Url\SecurityInfo">
        <arguments>
            <argument name="secureUrlList" xsi:type="array">
                <item name="multishipping_checkout" xsi:type="string">/multishipping/checkout</item>
            </argument>
        </arguments>
    </type>
    <virtualType name="multishippingPaymentSpecification" type="Magento\Payment\Model\Method\Specification\Composite">
        <arguments>
            <argument name="specifications" xsi:type="array">
                <item name="enabled" xsi:type="string">Magento\Multishipping\Model\Payment\Method\Specification\Enabled</item>
            </argument>
        </arguments>
    </virtualType>
    <type name="Magento\Multishipping\Block\Checkout\Billing">
        <arguments>
            <argument name="paymentSpecification" xsi:type="object">multishippingPaymentSpecification</argument>
        </arguments>
    </type>
    <type name="Magento\Multishipping\Model\Checkout\Type\Multishipping">
        <arguments>
            <argument name="paymentSpecification" xsi:type="object">multishippingPaymentSpecification</argument>
        </arguments>
    </type>
    <type name="Magento\Checkout\Controller\Cart\Add">
        <plugin name="multishipping_disabler" type="Magento\Multishipping\Plugin\DisableMultishippingMode" sortOrder="50" />
    </type>
    <type name="Magento\Checkout\Controller\Cart\UpdatePost">
        <plugin name="multishipping_disabler" type="Magento\Multishipping\Plugin\DisableMultishippingMode" sortOrder="50" />
    </type>
    <type name="Magento\Checkout\Controller\Index\Index">
        <plugin name="multishipping_disabler" type="Magento\Multishipping\Plugin\DisableMultishippingMode" sortOrder="50" />
    </type>
    <type name="Magento\Checkout\Model\Cart">
        <plugin name="multishipping_session_mapper" type="Magento\Multishipping\Model\Checkout\Type\Multishipping\Plugin" sortOrder="50" />
    </type>
    <type name="Magento\Checkout\Controller\Cart">
        <plugin name="multishipping_clear_addresses" type="Magento\Multishipping\Model\Cart\Controller\CartPlugin" sortOrder="50" />
    </type>
    <type name="Magento\Checkout\Controller\Sidebar\UpdateItemQty">
        <plugin name="multishipping_clear_addresses_before_update_qty" type="Magento\Multishipping\Model\Cart\Controller\MiniCartPlugin" sortOrder="50" />
    </type>
    <type name="Magento\Checkout\Controller\Sidebar\RemoveItem">
        <plugin name="multishipping_clear_addresses_before_remove_item" type="Magento\Multishipping\Model\Cart\Controller\MiniCartPlugin" sortOrder="50" />
    </type>
    <type name="Magento\Quote\Model\Quote">
        <plugin name="multishipping_reset_shipping_assigment" type="Magento\Multishipping\Plugin\ResetShippingAssigment"/>
    </type>
    <type name="Magento\Checkout\Controller\Cart\UpdateItemQty">
        <plugin name="multishipping_disabler" type="Magento\Multishipping\Plugin\DisableMultishippingMode" sortOrder="10" />
    </type>
</config>