<?php
use Microsoft\Graph\Beta\GraphServiceClient;
use Microsoft\Graph\Beta\Generated\RoleManagement\DeviceManagement\RoleAssignments\RoleAssignmentsRequestBuilderGetRequestConfiguration;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestConfiguration = new RoleAssignmentsRequestBuilderGetRequestConfiguration();
$queryParameters = RoleAssignmentsRequestBuilderGetRequestConfiguration::createQueryParameters();
$queryParameters->filter = "principalId eq '9e47fc6f-2d7a-464c-944e-d3dd0de522e4'";
$requestConfiguration->queryParameters = $queryParameters;
$result = $graphServiceClient->roleManagement()->deviceManagement()->roleAssignments()->get($requestConfiguration)->wait();