code: private boolean attributeValuesMatch(Set attributes, int runIndex1, int runIndex2) {
          Iterator iterator = attributes.iterator();
          while (iterator.hasNext()) {
              Attribute key = (Attribute) iterator.next();
             if (!valuesMatch(getAttribute(key, runIndex1), getAttribute(key, runIndex2))) {
                  return false;
              }
          }
          return true;
      }
docs: returns whether all specified attributes have equal values in the runs with the given indices