docs: public static File[] list(final String pFolder, final String pFilenameMask) throws FileNotFoundException {
          if (StringUtil.isEmpty(pFolder)) {
              return null;
          }
  
          File folder = resolve(pFolder);
          if (!(/*folder.exists() &&*/folder.isDirectory() && folder.canRead())) {
              // NOTE: exists is implicitly called by isDirectory
              throw new FileNotFoundException("\"" + pFolder + "\" is not a directory or is not readable.");
          }
  
          if (StringUtil.isEmpty(pFilenameMask)) {
              return folder.listFiles();
          }
  
          // TODO: Rewrite to use regexp
  
          FilenameFilter filter = new FilenameMaskFilter(pFilenameMask);
          return folder.listFiles(filter);
      }