code: void evalSeries(CmsSolrResultList resultList) {
  
          m_hasSeriesType = false;
          m_hasSeriesInstances = false;
          Set<CmsUUID> instanceIds = new HashSet<CmsUUID>();
          for (CmsSearchResource res : resultList) {
              String seriesType = res.getField(CmsSearchField.FIELD_SERIESDATES_TYPE);
              m_hasSeriesType = m_hasSeriesType || CmsStringUtil.isNotEmptyOrWhitespaceOnly(seriesType);
              if (m_hasSeriesType && I_CmsSerialDateValue.DateType.SERIES.name().equals(seriesType)) {
                  if (instanceIds.contains(res.getStructureId())) {
                      m_hasSeriesInstances = true;
                      break;
                  } else {
                      instanceIds.add(res.getStructureId());
                  }
              }
          }
          if (!m_hasSeriesInstances) {
              setsDateSeriesHiddenFlag(false);
          }
          m_toggleSeriesButton.setEnabled(m_hasSeriesInstances);
          m_toggleSeriesButton.setVisible(m_hasSeriesType);
  
      }
docs: Evaluates if date series types are present and if more than one instance of a series is in the search result.<p>
  
  @param resultList the search result list