How to get effective permission for the DriveItem that was shared with me (current session user)?

[23W]

I do this request await graphClient.Drives["{drive-id}"].Items["{driveItem-id}"].Permissions.GetAsync() to get permissions of shared with me driveItem .
This request returns collection of permission: owner permission and one or several write and read permission with collection of identities with whom this file was shared. The identities collection is Permission.GrantedToIdentitiesV2 that may contain easier User facet or SiteUser facet or both. For some reason Personal OneDrive does not contain User facet anymore (see #2828)
The question: how to get\find my (effective) permission from this mess?

I tried to identify my permission by matching current user Id (from graphClient.Me.Request().GetAsync()) and Id from SiteUser facet, but they are different,
I can try to use SiteUser.LoginName but seems its data is encoded like SharePoint claim and it is not documented somewhere in Ms Graph. SiteUser facet does not contain email field so i don't know how to find my permission.