Today, Fiddler exposes these two events to handle scenarios where the user is saving or loading a SAZ file.

        /// fires just before a SAZ file is saved
        public static event EventHandler<WriteSAZEventArgs> OnSaveSAZ;

        /// fires just after a SAZ file is loaded
        public static event EventHandler<ReadSAZEventArgs> OnLoadSAZ;

Equivalent event handlers should be created for the scenario where a user is Importing content into the Sessions list (e.g. using NetLog import or HAR import, etc). Otherwise, developers must undertake cumbersome workarounds to detect that a list of Sessions has been created/loaded from a file import, if, say, they wish to perform processing on those imported Sessions (adding custom properties or changing the display properties in the Session list).