 }
 
 
+
+
+
+
 // MARK: - YapDatabaseConnection
 
 extension YapDatabaseConnection {

    }

    /**
    Asynchronously reads all the items in the database for a particular Persistable Object.
    Example usage:

        connection.readAll() { (barcodes: [Barcode] in }

    :returns: An array of Object types.
    */
    public func asyncReadAll<Value where Value: Saveable, Value: Persistable, Value.ArchiverType.ValueType == Value>(queue: dispatch_queue_t = dispatch_get_main_queue(), completion: ([Value]) -> Void) {
        asyncRead({ $0.readAll() }, queue: queue, completion: completion)

    Synchronously returns an array of Value type for the given keys, with an array of keys which don't have
    corresponding values in the database.

        let (barcode: [Barcode], missing) = connection.filterExisting(keys)

    :param: keys An array of String instances
    :returns: An ([Value], [String]) tuple.
