code: public List<SessionTicketKey> parse(File file) throws IOException {
          return parseBytes(Files.toByteArray(file));
      }
docs: Returns a list of tickets parsed from the ticket file. The keys are returned in a format suitable for use
  with netty. The first keys are the current keys, following that are the new keys and old keys.
  
  @param file the ticket seed file.
  @return a list of ticket keys. Current keys are first, then new keys, then old keys.
  @throws IOException if reading the file or parsing the JSON fails.
  @throws IllegalArgumentException if the JSON file does not contain any current seeds.