code: public void debug( Marker marker, String msg )
      {
          if( m_delegate.isDebugEnabled() )
          {
              setMDCMarker( marker );
              m_delegate.debug( msg, null );
              resetMDCMarker();
          }
      }
docs: Log a message with the specific Marker at the DEBUG level.
  
  @param marker the marker data specific to this log statement
  @param msg    the message string to be logged