What is the preferred way to convert a message FileAttachment.ContentBytes to an actual file?

[catmanjan]

e.g:

var attachment = await graphClient.Users[userId].MailFolders[mailFolderId].Messages[messageId].Attachments[attachmentId]
    .GetAsync() as FileAttachment;

var bytes = attachment.ContentBytes;

at this point bytes is a "base-64 encoded contents of a file" - now I want to write this file to disk so it can be opened as normal, what is the preferred method for doing so?

Perhaps there is a helper method somewhere in the SDK I can use?