<?php
use Microsoft\Graph\Beta\GraphServiceClient;
use Microsoft\Graph\Beta\Generated\Users\Item\Calendar\Events\EventsRequestBuilderGetRequestConfiguration;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestConfiguration = new EventsRequestBuilderGetRequestConfiguration();
$queryParameters = EventsRequestBuilderGetRequestConfiguration::createQueryParameters();
$queryParameters->filter = "startsWith(subject,'All')";
$requestConfiguration->queryParameters = $queryParameters;
$result = $graphServiceClient->me()->calendar()->events()->get($requestConfiguration)->wait();