 
     /// Deletes zero or more objects from the Realm.
     ///
+    /// - Warning: This method is not thread safe for now. It is not better to pass object directly.
+    ///  If you want to use this method safely, you should call `realm.run(io:)` in a same thread, or 
+    ///  use with `flatMap`.
     /// - Parameter objects: A `Results` containing the objects to be deleted.
     /// - Returns: `Write` operation
     public static func delete<T: Object>(_ objects: Results<T>) -> RealmWrite<Void> {


    /// Deletes zero or more objects from the Realm.
    ///
    /// - Parameter objects: A list of objects to delete.
    /// - Returns: `Write` operation
    public static func delete<T: Object>(_ objects: List<T>) -> RealmWrite<Void> {


    /// Adds all the objects in a collection into the Realm.
    ///
    /// - Warning: This method is not thread safe for now. It is not better to pass object directly.
    ///  If you want to use this method safely, you should call `realm.run(io:)` in a same thread, or 
    ///  use with `flatMap`.
    /// - Parameter objects: A sequence which contains objects to be added to the Realm.
    /// - Returns: `Write` operation
    public static func add<S>(_ objects: S) -> RealmWrite<Void> where S: Sequence, S.Iterator.Element: Object {
