Is there a way to get all Internet Message Headers of an item attachment?

Question

I have a requirement to read all Internet Message Headers of an Item Attachment. Using following query, it is possible to get headers. But not all.

var itemAttachment = await graphServiceClient.Users["id"]
                .Messages[messageId]
                .Attachments[messageWithItemAttachment[0].Id]
                .Request()
                .Expand($"microsoft.graph.itemAttachment/item")
                .GetAsync();

I have found following resource which provides a way to read missing headers of an item. Get message using Graph missing some InternetMessageHeaders

I need to know how can I use such expansion within a expand query?