     // MARK: - Enumeration
     
     open func enumerateKeys(backward: Bool, startingAtKey key: String?, andPrefix prefix: String?, usingBlock block: LevelDBKeyBlock) {
+        NSLog("LevelDB enumerateKeys. backward: \(backward) startingAtKey key: \(key) perfix: \(prefix)")
         self.enumerateKeysWithPredicate(nil, backward: backward, startingAtKey: key, andPrefix: prefix, usingBlock: block)
     }
     

            let fileManager = FileManager.default
            try fileManager.removeItem(atPath: path)
        } catch {
            print("error deleting database at path \(path), \(error)")
        }
    }
    

    
    open func enumerateKeysAndValuesLazily(backward: Bool, startingAtKey key: String?, andPrefix prefix: String?, usingBlock block:LevelDBLazyKeyValueBlock) {
        guard let db = db else {
            NSLog("Database reference is not existent (it has probably been closed)")
            return
        }
        let iterator = levelDBIteratorNew(db)
        var stop = false
        guard let iteratorPointer = iterator else {
            NSLog("iterator is nil")
            return
        }
        _startIterator(iteratorPointer, backward: backward, prefix: prefix, start: key)
