/// <param name="DocumentKey">The key of the document that failed, for a file its full path, or the name of the data source when the failure was not about one document.</param>
/// <param name="ExtractionCode">Why reading the document failed, where the failure was about reading it at all.</param>
/// <param name="IsPermanent">Whether the document stays out of the index until it changes.</param>
/// <param name="DisplayName">How the document is called for the user, e.g. the name of a file or the subject of a mail. Empty where the run did not know it, e.g. for a failure stored by an earlier run.</param>