code: public void setSlf4jLogname(String logName)
      {
          // use length() == 0 instead of isEmpty() for Java 5 compatibility
          if( logName.length() == 0 )
          {
              m_log = null;
          }
          else
          {
              m_log = LoggerFactory.getLogger(logName);
          }
      }
docs: Set the name of the logger that this logger should log to.
  If you set it to an empty string, will shut up completely.