code: public static void decodeToFile (@Nonnull final String sDataToDecode, @Nonnull final File aFile) throws IOException
    {
      try (final Base64OutputStream bos = new Base64OutputStream (FileHelper.getBufferedOutputStream (aFile), DECODE))
      {
        bos.write (sDataToDecode.getBytes (PREFERRED_ENCODING));
      }
    }
docs: Convenience method for decoding data to a file.
  <p>
  As of v 2.3, if there is a error, the method will throw an IOException.
  <b>This is new to v2.3!</b> In earlier versions, it just returned false,
  but in retrospect that's a pretty poor way to handle it.
  </p>
  
  @param sDataToDecode
  Base64-encoded data as a string
  @param aFile
  File for saving decoded data
  @throws IOException
  if there is an error
  @since 2.1