docs: public <T> QueryCriteria addParameter( String listId, T... param ) {
          if( param.length == 0 ) {
              return null;
          }
          if( QueryCriteriaType.REGEXP.equals(this.type) && ! (param[0] instanceof String) ) {
              throw new IllegalArgumentException("Only String parameters may be used in regular expressions.");
          }
          QueryCriteria criteria =  new QueryCriteria(listId, this.union, this.type, param.length);
          for( T paramElem : param ) {
             criteria.addParameter(paramElem);
          }
          addCriteria(criteria);
          return criteria;
      }