public static Task<TResult> Then<TSource, TResult>(
	this Task<TSource> task,
	Func<Task<TSource>, Task<TResult>> continuationFunction
)

<ExtensionAttribute>
Public Shared Function Then(Of TSource, TResult) ( 
	task As Task(Of TSource),
	continuationFunction As Func(Of Task(Of TSource), Task(Of TResult))
) As Task(Of TResult)

public:
[ExtensionAttribute]
generic<typename TSource, typename TResult>
static Task<TResult>^ Then(
	Task<TSource>^ task, 
	Func<Task<TSource>^, Task<TResult>^>^ continuationFunction
)

[<ExtensionAttribute>]
static member Then : 
        task : Task<'TSource> * 
        continuationFunction : Func<Task<'TSource>, Task<'TResult>> -> Task<'TResult>