code: public void error( Marker marker, String format, Object arg )
      {
          if( m_delegate.isErrorEnabled() )
          {
              FormattingTuple tuple = MessageFormatter.format( format, arg );
              setMDCMarker( marker );
              m_delegate.error( tuple.getMessage(), tuple.getThrowable() );
              resetMDCMarker();
          }
      }
docs: This method is similar to {@link #error(String, 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 arg    the argument