protected override void OnExecute(CommandProcessor commandProcessor)
        {
            _instanceXml = _studyXml.FindInstanceXml(_seriesInstanceUid, _sopInstanceUid);

            _studyXml.RemoveInstance(_seriesInstanceUid, _sopInstanceUid);

            // flush it into disk
            // Write it back out.  We flush it out with every added image so that if a failure happens,
            // we can recover properly.
            if (!commandProcessor.ExecuteSubCommand(this, new SaveXmlCommand(_studyXml, _studyLocation)))
            {
                throw new ApplicationException(commandProcessor.FailureReason);
            }
        }