code: protected List<ExcelFile> getExcelFiles() {
  		if (excelFiles == null) {
  			excelFiles = newArrayListWithCapacity(3);
  
  			for (int i = 0;; ++i) {
  				String baseKey = String.format("dataSource.%s.%d", getName(), i);
  				String path = configuration.get(baseKey + ".path");
  				if (path == null) {
  					break;
  				}
  				String doString = configuration.get(baseKey + ".dataOrientation", "rowbased");
  				DataOrientation dataOrientation = DataOrientation.valueOf(doString);
  
  				log.info("Opening Excel file: {}", path);
  				ExcelFile file = new ExcelFile(new File(path), dataOrientation, dataFormatter);
  
  				try {
  					file.load();
  				} catch (InvalidFormatException ex) {
  					throw new JFunkException(ex.getMessage(), ex);
  				} catch (IOException ex) {
  					throw new JFunkException(ex.getMessage(), ex);
  				}
  
  				excelFiles.add(file);
  			}
  		}
  		return excelFiles;
  	}
docs: Loads and cache Excel file contents.
  
  @return a list of {@link ExcelFile} instances