/** Collects all the StarTree leaves that match the provided dimension values */
 private void findMatchingLeaves(
     StarTreeIndexNode node, List<Integer> values, Set<StarTreeIndexNode> leaves) {
   if (node.isLeaf()) {
     leaves.add(node);
   } else {
     Integer value = values.get(node.getChildDimensionName());
     findMatchingLeaves(node.getChildren().get(value), values, leaves);
     findMatchingLeaves(node.getChildren().get(StarTreeIndexNode.all()), values, leaves);
   }
 }