code: public void trace( Marker marker, String format, Object arg1, Object arg2 )
      {
          if( m_delegate.isTraceEnabled() )
          {
              FormattingTuple tuple = MessageFormatter.format( format, arg1, arg2 );
              setMDCMarker( marker );
              m_delegate.trace( tuple.getMessage(), tuple.getThrowable() );
              resetMDCMarker();
          }
      }
docs: This method is similar to {@link #trace(String, Object, Object)}
  method except that the marker data is also taken into
  consideration.
  
  @param marker the marker data specific to this log statement
  @param format the format string
  @param arg1   the first argument
  @param arg2   the second argument