public static void Log(this ILogger logger, TraceEventType eventType, string message, string category)
 {
     if (category == null)
     {
         logger.WriteEntry(new LogEntry()
         {
             EventType = eventType,
             Message   = message
         });
     }
     else
     {
         using (LogicalOperation.Create(category, new object[0]))
             logger.WriteEntry(new LogEntry()
             {
                 EventType = eventType,
                 Message   = message
             });
     }
 }