presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/cache/CachingHiveMetastore.java/CachingHiveMetastore/getDatabase
class CachingHiveMetastore:    @Override
    public Optional<Database> getDatabase(String databaseName)
    {
        return get(databaseCache, databaseName);
    }