code: public String getTooltip() {
          final String key = "pm.field." + getEntity().getId() + "." + getId() + ".tooltip";
          if (key == null) {
              return null;
          }
          final String message = getPm().message(key);
          if (key.equals(message)) {
              return null;
          }
          return message;
      }
docs: Returns the internationalized field tooltip