How to add a the query options to my graphclient request

I'm trying a to add query options to my graphclient. According to the documentation, this should be possible. However, I always get the message that the request property is no longer present in the Microsoft.Graph nuget. Which is strange. Downgrading to older versions does not help.

I'm trying to do something like this:

var options = new List<QueryOption>
{
  new QueryOption("$select=internetMessageHeaders")
}

var mimeContent = await graphClient
               .Users[TestProperties.UserEmail]
               .Messages[specificMailResponse.Id]
               .Request(options)
               .GetAsync();

Can anyone tell me what I am doing wrong and why the request property no longer exists?

I'm using Microsoft.Graph 5.0.0-preview.10

At the end of the documentation my example is described https://github.com/microsoftgraph/msgraph-sdk-dotnet/blob/dev/docs/upgrade-to-v4.md