public override string Format(LogMessage message)
            {
                StringBuilder builder = new StringBuilder();

                builder.AppendFormat("{0}", message.LogLevel.ToString()[0]);
                builder.Append(" | ");
                builder.AppendFormat("{0}", String.IsNullOrWhiteSpace(message.User) ? "UNKNOWN" : message.User);
                builder.Append(" | ");
                builder.AppendFormat("{0} {1}", message.TimeStamp.ToLongTimeString(), message.TimeStamp.ToShortDateString());
                builder.Append(" | ");
                builder.AppendFormat("[{0}]", message.LoggerName);
                builder.AppendFormat(" - {0}", message.Message);

                return builder.ToString();
            }
 public abstract String Format(LogMessage message);