     ///
     /// - e.g. task.progress { oldProgress, newProgress in ... }
     ///
-    /// NOTE: `oldProgress` is always nil when `weakified = true`
+    /// - Note: `oldProgress` is always nil when `weakified = true`
+    /// - Returns: Self (same `Task`)
     ///
     public func progress(progressClosure: ProgressTuple -> Void) -> Self
     {

    }
    
    ///
    /// creates rejected task (non-paused)
    ///
    /// - e.g. Task<P, V, E>(error: someError)
    ///

    }
    
    ///
    /// `then` (fulfilled & rejected) + closure returning **task**.
    /// (similar to `flatMap` in functional programming)
    ///
    /// - e.g. task.then { value, errorInfo -> NextTaskType in ... }
    ///
    /// - Returns: New `Task`
    ///
    public func then<Progress2, Value2, Error2>(thenClosure: (Value?, ErrorInfo?) -> Task<Progress2, Value2, Error2>) -> Task<Progress2, Value2, Error2>
    {
