code: public static List<File> ensureWriteableDirectory(List<File> dirs)
      throws IOException {
          for (Iterator<File> i = dirs.iterator(); i.hasNext();) {
               FileUtils.ensureWriteableDirectory(i.next());
          }
          return dirs;
      }
docs: Ensure writeable directories.
  
  If doesn't exist, we attempt creation.
  
  @param dirs List of Files to test.
  
  @return The passed <code>dirs</code>.
  
  @exception IOException If passed directory does not exist and is not
  createable, or directory is not writeable or is not a directory.