if( path!= null || filename!=null || fileExt!=null )
this.writerDesc = new WriterDescriptor( path, filename, fileExt, exprLanguage);
if( template!=null && inlineTemplate!= null )
throw new EngineException( tag + " Exactly one of 'template' or 'body template' should be specified." );
if( template==null && inlineTemplate== null )
throw new EngineException( tag + " Exactly one of 'template' or 'body template' should be specified." );
if( writerName!=null && writerDesc!= null )
throw new EngineException( tag + " Only one of 'writerName' or 'writerDesc' should be specified." );
super.engineStart(context);
}