code: @Nonnull
      public JsonToken expect(String message) throws JsonException, IOException {
          if (!hasNext()) {
              throw newParseException("Expected %s: Got end of file", message);
          }
          JsonToken tmp = unreadToken;
          unreadToken = null;
          return tmp;
      }
docs: Expect a new JSON token on the stream.
  
  @param message Message to add to exception if there are no more JSON
  tokens on the stream.
  @return The next token.
  @throws JsonException If no more tokens, or the token is illegally
  formatted.
  @throws IOException If unable to read from stream.