code: public void trace( String format, Object[] argArray )
      {
          if( m_delegate.isTraceEnabled() )
          {
              FormattingTuple tuple = MessageFormatter.arrayFormat( format, argArray );
              m_delegate.trace( tuple.getMessage(), tuple.getThrowable() );
          }
      }
docs: Log a message at the TRACE level according to the specified format
  and arguments.
  
  <p>This form avoids superfluous object creation when the logger
  is disabled for the TRACE level. </p>
  
  @param format   the format string
  @param argArray an array of arguments