code: public static String[] readTags(JsonParser parser)
          throws IOException, JsonReadException
      {
          if (parser.getCurrentToken() != JsonToken.FIELD_NAME) {
              return null;
          }
          if (!".tag".equals(parser.getCurrentName())) {
              return null;
          }
          parser.nextToken();
          if (parser.getCurrentToken() != JsonToken.VALUE_STRING) {
              throw new JsonReadException("expected a string value for .tag field", parser.getTokenLocation());
          }
          String tag = parser.getText();
          parser.nextToken();
          return tag.split("\\.");
      }
docs: Helper to read and parse the optional ".tag" field. If one is found, positions the parser
  at the next field (or the closing brace); otherwise leaves the parser position unchanged.
  Returns null if there isn't a ".tag" field; otherwise an array of strings (the tags).
  Initially the parser must be positioned right after the opening brace.