anchor.diff:  
     @ApiMethod(method: 'GET', path: 'byAnalysis/{product}/{model}/{analysis}')
     Future<List<TimeseriesAssembly>> byAnalysis(String product, String model, String analysis, {String locations, String elements, String validFrom, String validTo}) {
  +    try {
         if ((locations == null) || (elements == null)) {
           throw new FormatException("locations and elements are required query paramters");
         }
  
positive.code:       List<TimeseriesNode> nodes = _extractNodes(locations, elements, product, model);
  
        return cache.getTimeseriesBestSeriesSet(nodes, validFromAt, duration);
      }catch( e){
        print( "had exception ${e}");
        throw new ApplicationError( new Exception(e));      
      }
    }
  
  
negative.code:       throw new FormatException("Time value of '${time}' is invalid, must be ISO time format");
      }
    }
  }
  