useGetMe.swift

GraphManager.instance.getMe { completion:
      (user: MSGraphUser?, error: Error?) in

      DispatchQueue.main.async {
          guard let currentUser = user, error == nil else {
       // Failed to get user 
              print("Error getting user: \(String(describing: error))")
              return
          }

     // Got user information in "currentUser" successfully
      }
}