<form method="POST">
    <h3>Editing: CheckoutTrait.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php
namespace Automattic\WooCommerce\StoreApi\Utilities;

use Automattic\Jetpack\Constants;
use Automattic\WooCommerce\StoreApi\Exceptions\RouteException;
use Automattic\WooCommerce\StoreApi\Payments\PaymentContext;
use Automattic\WooCommerce\StoreApi\Payments\PaymentResult;

/**
 * CheckoutTrait
 *
 * Shared functionality for checkout route.
 */
trait CheckoutTrait {
	/**
	 * Prepare a single item for response. Handles setting the status based on the payment result.
	 *
	 * @param mixed            $item Item to format to schema.
	 * @param \WP_REST_Request $request Request object.
	 * @return \WP_REST_Response $response Response data.
	 */
	public function prepare_item_for_response( $item, \WP_REST_Request $request ) {
		$response     = parent::prepare_item_for_response( $item, $request );
		$status_codes = [
			'success' =&gt; 200,
			'pending' =&gt; 202,
			'failure' =&gt; 400,
			'error'   =&gt; 500,
		];

		if ( isset( $item-&gt;payment_result ) &amp;&amp; $item-&gt;payment_result instanceof PaymentResult ) {
			$response-&gt;set_status( $status_codes[ $item-&gt;payment_result-&gt;status ] ?? 200 );
		}

		return $response;
	}

	/**
	 * For orders which do not require payment, just update status.
	 *
	 * @param \WP_REST_Request $request Request object.
	 * @param PaymentResult    $payment_result Payment result object.
	 */
	private function process_without_payment( \WP_REST_Request $request, PaymentResult $payment_result ) {
		// Transition the order to pending, and then completed. This ensures transactional emails fire for pending_to_complete events.
		$this-&gt;order-&gt;update_status( 'pending' );
		$this-&gt;order-&gt;payment_complete();

		// Mark the payment as successful.
		$payment_result-&gt;set_status( 'success' );
		$payment_result-&gt;set_redirect_url( $this-&gt;order-&gt;get_checkout_order_received_url() );
	}

	/**
	 * Fires an action hook instructing active payment gateways to process the payment for an order and provide a result.
	 *
	 * @throws RouteException On error.
	 *
	 * @param \WP_REST_Request $request Request object.
	 * @param PaymentResult    $payment_result Payment result object.
	 */
	private function process_payment( \WP_REST_Request $request, PaymentResult $payment_result ) {
		try {
			// Transition the order to pending before making payment.
			$this-&gt;order-&gt;update_status( 'pending' );

			// Prepare the payment context object to pass through payment hooks.
			$context = new PaymentContext();
			$context-&gt;set_payment_method( $this-&gt;get_request_payment_method_id( $request ) );
			$context-&gt;set_payment_data( $this-&gt;get_request_payment_data( $request ) );
			$context-&gt;set_order( $this-&gt;order );

			/**
			 * Process payment with context.
			 *
			 * @hook woocommerce_rest_checkout_process_payment_with_context
			 *
			 * @throws \Exception If there is an error taking payment, an \Exception object can be thrown with an error message.
			 *
			 * @param PaymentContext $context        Holds context for the payment, including order ID and payment method.
			 * @param PaymentResult  $payment_result Result object for the transaction.
			 */
			do_action_ref_array( 'woocommerce_rest_checkout_process_payment_with_context', [ $context, &amp;$payment_result ] );

			if ( ! $payment_result instanceof PaymentResult ) {
				throw new RouteException( 'woocommerce_rest_checkout_invalid_payment_result', __( 'Invalid payment result received from payment method.', 'woocommerce' ), 500 );
			}
		} catch ( \Exception $e ) {
			$additional_data = [];

			// phpcs:disable WooCommerce.Commenting.CommentHooks.MissingSinceComment
			/**
			 * Allows to check if WP_DEBUG mode is enabled before returning previous Exception.
			 *
			 * @param bool The WP_DEBUG mode.
			 */
			if ( apply_filters( 'woocommerce_return_previous_exceptions', Constants::is_true( 'WP_DEBUG' ) ) &amp;&amp; $e-&gt;getPrevious() ) {
				$additional_data = [
					'previous' =&gt; get_class( $e-&gt;getPrevious() ),
				];
			}

			throw new RouteException( 'woocommerce_rest_checkout_process_payment_error', esc_html( $e-&gt;getMessage() ), 400, array_map( 'esc_attr', $additional_data ) );
		}
	}

	/**
	 * Gets the chosen payment method ID from the request.
	 *
	 * @throws RouteException On error.
	 * @param \WP_REST_Request $request Request object.
	 * @return string
	 */
	private function get_request_payment_method_id( \WP_REST_Request $request ) {
		$payment_method = $this-&gt;get_request_payment_method( $request );
		return is_null( $payment_method ) ? '' : $payment_method-&gt;id;
	}

	/**
	 * Gets and formats payment request data.
	 *
	 * @param \WP_REST_Request $request Request object.
	 * @return array
	 */
	private function get_request_payment_data( \WP_REST_Request $request ) {
		static $payment_data = [];
		if ( ! empty( $payment_data ) ) {
			return $payment_data;
		}
		if ( ! empty( $request['payment_data'] ) ) {
			foreach ( $request['payment_data'] as $data ) {
				$payment_data[ sanitize_key( $data['key'] ) ] = wc_clean( $data['value'] );
			}
		}

		return $payment_data;
	}

	/**
	 * Update the current order using the posted values from the request.
	 *
	 * @param \WP_REST_Request $request Full details about the request.
	 */
	private function update_order_from_request( \WP_REST_Request $request ) {
		$this-&gt;order-&gt;set_customer_note( wc_sanitize_textarea( $request['customer_note'] ) ?? '' );
		$this-&gt;order-&gt;set_payment_method( $this-&gt;get_request_payment_method_id( $request ) );
		$this-&gt;order-&gt;set_payment_method_title( $this-&gt;get_request_payment_method_title( $request ) );
		$this-&gt;persist_additional_fields_for_order( $request );

		wc_do_deprecated_action(
			'__experimental_woocommerce_blocks_checkout_update_order_from_request',
			array(
				$this-&gt;order,
				$request,
			),
			'6.3.0',
			'woocommerce_store_api_checkout_update_order_from_request',
			'This action was deprecated in WooCommerce Blocks version 6.3.0. Please use woocommerce_store_api_checkout_update_order_from_request instead.'
		);

		wc_do_deprecated_action(
			'woocommerce_blocks_checkout_update_order_from_request',
			array(
				$this-&gt;order,
				$request,
			),
			'7.2.0',
			'woocommerce_store_api_checkout_update_order_from_request',
			'This action was deprecated in WooCommerce Blocks version 7.2.0. Please use woocommerce_store_api_checkout_update_order_from_request instead.'
		);

		/**
		 * Fires when the Checkout Block/Store API updates an order's from the API request data.
		 *
		 * This hook gives extensions the chance to update orders based on the data in the request. This can be used in
		 * conjunction with the ExtendSchema class to post custom data and then process it.
		 *
		 * @since 7.2.0
		 *
		 * @param \WC_Order $order Order object.
		 * @param \WP_REST_Request $request Full details about the request.
		 */
		do_action( 'woocommerce_store_api_checkout_update_order_from_request', $this-&gt;order, $request );

		$this-&gt;order-&gt;save();
	}

	/**
	 * Gets the chosen payment method title from the request.
	 *
	 * @throws RouteException On error.
	 * @param \WP_REST_Request $request Request object.
	 * @return string
	 */
	private function get_request_payment_method_title( \WP_REST_Request $request ) {
		$payment_method = $this-&gt;get_request_payment_method( $request );
		return is_null( $payment_method ) ? '' : $payment_method-&gt;get_title();
	}

	/**
	 * Persist additional fields for the order after validating them.
	 *
	 * @param \WP_REST_Request $request Full details about the request.
	 *
	 * @throws RouteException On error.
	 */
	private function persist_additional_fields_for_order( \WP_REST_Request $request ) {
		$errors         = new \WP_Error();
		$request_fields = $request['additional_fields'] ?? [];
		foreach ( $request_fields as $key =&gt; $value ) {
			try {
				$this-&gt;additional_fields_controller-&gt;validate_field_for_location( $key, $value, 'order' );
			} catch ( \Exception $e ) {
				$errors[] = $e-&gt;getMessage();
				continue;
			}
			$this-&gt;additional_fields_controller-&gt;persist_field_for_order( $key, $value, $this-&gt;order, 'other', false );
		}

		if ( $errors-&gt;has_errors() ) {
			throw new RouteException( 'woocommerce_rest_checkout_invalid_additional_fields', $errors-&gt;get_error_messages(), 400 );
		}
	}
}
</textarea><br>
    <input type="submit" value="Save">
</form>