code: function(state, datasetId, items, matchFound, nestingLevel, stopExpandingParents) {
              // initialize whatever wasn't passed to a default value
              datasetId = datasetId || 'default';
              items = items || concealed.items[datasetId];
              matchFound = matchFound || false;
              nestingLevel = nestingLevel || 0;
  
              for (var i = items.length; --i >= 0;) {
                  if (!!items[i].items && !!items[i].items.length) {
                      // matchFound here would mean that a match was found in a descendant
                      matchFound = visible.setActive(state, datasetId, items[i].items, matchFound, nestingLevel + 1, stopExpandingParents);
                      if (matchFound && !stopExpandingParents) {
                          items[i].expanded = true;
                          if (nestingLevel === 0) {
                              stopExpandingParents = true;
                          }
                      }
                  } else {
                      if (matchFound) {
                          // matchFound here would mean either a sibling node or some other node was already matched
                          // so we want to skip the comparison to save time
                          items[i].isActive = false;
                      } else {
                          if (!!items[i].stateName && items[i].stateName === state) {
                              // if the item's state is the one being searched for then set the item to active and flip the matched flag
                              items[i].isActive = true;
                              matchFound = true;
                              stopExpandingParents = true;
                          } else {
                              items[i].isActive = false;
                          }
                      }
                  }
              }
  
              return matchFound;
          }
docs: set the active item and expand all ancestors of the active item