code: private List<String> addPath(List<String> filenames, String additionalPath) {
          ArrayList<String> newFilenames = new ArrayList<String>(filenames.size());
          for (String filename : filenames) {
              newFilenames.add(additionalPath + '/' + filename);
          }
  
          return newFilenames;
      }
docs: Modifies a String list of filenames to include an additional path.
  
  @param filenames
  @param additionalPath
  @return