How can TiKV be ACID if RocksDB is not ACID?

BadgerDB says that RocksDB is not ACID, then I wonder how TiKV can be said ACID, can you elaborate ?

Distributed ACID transaction

Transaction of TiKV adopts the model used by Google in BigTable: Percolator. TiKV’s implementation is inspired by this paper, with a lot of optimizations. See transaction overview for details.

TiKV implement several layers upon rocksdb, including Raft-replication, Transaction layer and Coprocessor(SQL logic handling)