code: public Integer getIntReqPar(final String name,
                                final String errProp) throws Throwable {
      try {
        return super.getIntReqPar(name);
      } catch (final Throwable t) {
        getErr().emit(errProp, getReqPar(name));
        return null;
      }
    }
docs: Get an Integer request parameter or null. Emit error for non-null and
  non integer
  
  @param name    name of parameter
  @param errProp error to emit
  @return  Integer   value or null
  @throws Throwable on error