public Task<T> Cache<T>(
	Expression<Func<Task<T>>> action,
	[CallerMemberNameAttribute] string memberName = ""
)
where T : class

Public Function Cache(Of T As Class) ( 
	action As Expression(Of Func(Of Task(Of T))),
	<CallerMemberNameAttribute> Optional memberName As String = ""
) As Task(Of T)

public:
generic<typename T>
where T : ref class
Task<T>^ Cache(
	Expression<Func<Task<T>^>^>^ action, 
	[CallerMemberNameAttribute] String^ memberName = L""
)

member Cache : 
        action : Expression<Func<Task<'T>>> * 
        [<CallerMemberNameAttribute>] ?memberName : string 
(* Defaults:
        let _memberName = defaultArg memberName ""
*)
-> Task<'T>  when 'T : not struct