docs: private JsonToken readingConstant(JsonTokenType type, JsonToken token) {
          try {
              int numCharsToRead = ((String) type.getValidator()).length();
              char[] chars = new char[numCharsToRead];
              reader.read(chars);
              String stringRead = new String(chars);
  
              if (stringRead.equals(type.getValidator())) {
                  token.setEndColumn(token.getStartColumn() + numCharsToRead);
                  token.setText(stringRead);
                  return token;
              } else {
                  throwJsonException(stringRead, type);
              }
          } catch (IOException ioe) {
              throw new JsonException("An IO exception occurred while reading the JSON payload", ioe);
          }
          return null;
      }