040000 tree 1f222a811bb4292b34b41fe8668750887248b0a8	frequencies
040000 tree fc3d6138b43c1b4285c17d8123d4029747f7d3e0	hash
040000 tree ab8bb247b46cac87acaba47bb1179ccf7da435f8	hll
040000 tree 77268de47e741701733bac6cfd33f51f9a54cbcd	quantiles
040000 tree c0b9f957ab398ead218e1808e0004dd31149e7b0	sampling
040000 tree e8fcea89a22e2d6995f87914330db9de3e65c580	theta
040000 tree 8e7a744320329443418cbe363337ef528c347d26	tuple