<?php
use Microsoft\Graph\Beta\GraphServiceClient;
use Microsoft\Graph\Beta\Generated\Models\Security\EdiscoveryHoldPolicy;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new EdiscoveryHoldPolicy();
$requestBody->setDescription('updated description');
$requestBody->setContentQuery('updated kql query');
$result = $graphServiceClient->security()->cases()->ediscoveryCases()->byEdiscoveryCaseId('ediscoveryCase-id')->legalHolds()->byEdiscoveryHoldPolicyId('ediscoveryHoldPolicy-id')->patch($requestBody)->wait();