I want to add a new segmentId (with the same name) into my mapping array but with a different elementId but same method

Below is the MapperInterface.php

I'm trying to figure out how to add an if else statement into the const. mapping array. Something like so:

if (LIN02 == “VN”) 
o   Treat LIN03 as the SKU
·         else if (LIN04 == “VN”) 
o   Treat LIN05 as the SKU

---

<?php

declare(strict_types=1);

namespace Direct\OrderUpdate\Api;

use Direct\OrderUpdate\Api\OrderUpdateInterface;

/**
 * Interface MapperInterface
 * Translates parsed edi file data to a \Direct\OrderUpdate\Api\OrderUpdateInterface
 * @package Direct\OrderUpdate\Api
 */
interface MapperInterface
{
    /**
     * Mapping array formatted as MAPPING[segemntId][elemntId] => methodNameToProcessTheValueOfElement
     * @var array
     */
    const MAPPING = [
        'DTM' => ['DTM02' => 'processCreatedAt'],   // shipment.created_at
        'PRF' => ['PRF01' => 'processIncrementId'], // order.increment_id
        'LIN' => ['LIN05' => 'processSku'],         // shipment.items.sku
        'SN1' => ['SN102' => 'processQty'],         // shipment.items.qty
        'REF' => ['REF02' => 'processTrack']        // shipment.tracks.track_number, shipment.tracks.carrier_code
    ];

    /**
     * Mapping for carrier codes
     * @var array
     */
    const CARRIER_CODES_MAPPING = ['FED' => 'fedex'];

    /**
     * @return array
     */
    public function getMapping(): array;

    /**
     * @param array $segments
     * @return OrderUpdateInterface
     */
    public function map(array $segments): OrderUpdateInterface;
}

I hope that makes sense. Not sure if their is a better way to go about it but ultimately i need more than 1 "LIN" segmentId. Maybe add a new function and use this condition?

from I want to add a new segmentId (with the same name) into my mapping array but with a different elementId but same method