040000 tree 685a1f133773442910f34306acc79dc31232b8bf	frequencies
040000 tree 4f0c31626772f29da44773f0e9546ab349785003	hash
040000 tree 526ac5f0e18e2bf1bc58c72bbd9c21d979965ddb	quantiles
040000 tree c1ab41afdd98d34e1b7d70289d188aef27804852	sampling
040000 tree 43a99185761253d45d0ce048f084e617a15750df	theta
040000 tree 3f4e87f7577f731a9a39de36a374a6a74e0f72fd	tuple