code: func loadSnapshot(config *params.CliqueConfig, sigcache *lru.ARCCache, db ethdb.Database, hash common.Hash) (*Snapshot, error) {
  	blob, err := db.Get(append([]byte("clique-"), hash[:]...))
  	if err != nil {
  		return nil, err
  	}
  	snap := new(Snapshot)
  	if err := json.Unmarshal(blob, snap); err != nil {
  		return nil, err
  	}
  	snap.config = config
  	snap.sigcache = sigcache
  
  	return snap, nil
  }
docs: // loadSnapshot loads an existing snapshot from the database.