<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Chats\Item\Messages\MessagesRequestBuilderGetRequestConfiguration;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestConfiguration = new MessagesRequestBuilderGetRequestConfiguration();
$headers = [
'Prefer' => 'include-unknown-enum-members',
];
$requestConfiguration->headers = $headers;
$queryParameters = MessagesRequestBuilderGetRequestConfiguration::createQueryParameters();
$queryParameters->top = 2;
$requestConfiguration->queryParameters = $queryParameters;
$result = $graphServiceClient->chats()->byChatId('chat-id')->messages()->get($requestConfiguration)->wait();