pub fn pruner(&mut self) -> (MerkleTreePruner<RocksDBWrapper>, MerkleTreePrunerHandle) {
        assert!(
            !self.pruning_enabled,
            "pruner was already obtained for the tree"
        );
        self.pruning_enabled = true;
        let db = self.tree.db.inner().clone();
        MerkleTreePruner::new(db)
    }
Returns tree pruner and a handle to stop it.

# Panics

Panics if this method was already called for the tree instance; it's logically unsound to run
multiple pruners for the same tree concurrently.
core/lib/merkle_tree/src/domain.rs