/**
   * @param fld Folder with files to match.
   * @param ptrn Pattern to match against file name.
   * @return Collection of matched files.
   */
  public static List<VisorLogFile> matchedFiles(File fld, final String ptrn) {
    List<VisorLogFile> files =
        fileTree(
            fld,
            MAX_FOLDER_DEPTH,
            new FileFilter() {
              @Override
              public boolean accept(File f) {
                return !f.isHidden()
                    && (f.isDirectory() || f.isFile() && f.getName().matches(ptrn));
              }
            });

    Collections.sort(files, LAST_MODIFIED);

    return files;
  }