code: function findEntriesByCheck(groups, compareFn) {
      var foundEntries = [],
          newEntries;
      groups.forEach(function(group) {
          newEntries = group.getEntries().filter(compareFn);
          if (newEntries.length > 0) {
              foundEntries = foundEntries.concat(newEntries);
          }
          newEntries = findEntriesByCheck(group.getGroups(), compareFn);
          if (newEntries.length > 0) {
              foundEntries = foundEntries.concat(newEntries);
          }
      });
      return foundEntries;
  }
docs: Find entry instances by filtering with a compare function
  @param {Array.<Group>} groups The groups to check in
  @param {Function} compareFn The callback comparison function, return true to keep and false
  to strip
  @returns {Array.<Entry>} An array of found entries