Throws() bug for a NotImplemented Func<Task>

[chris-findlay]

PAssert.Throws<TException>(Action a, ...) has the expected try/catch structure, but PAssert.Throws<TException>(Func<Task> a, ...) does not - the latter handles the case of the task faulting, but does not work if the code returning the task fails in any synchronous way, e.g:

public Task DoSomethingAsync() { throw new NotImplementedException(); }
---
[Test]
public void TestIt() {
    PAssert.Throws<NotImplementedException>(() => obj.DoSomethingAsync());
}

This results in the NIE bubbling up out of the Throws call, as it doesn't check that the setup works, only that the resulting task does (or rather doesn't - i.e. that the Task faults).

[chris-findlay]

I tried wrapping the content of Throws<>(Func<Task>...) in a try catch like the other one, but the catch needs to return a Task<TException> and not just TException, so I used Task.FromResult(), but get a compile error that says
error CS0117: 'Task' does not contain a definition for 'FromResult'
which I completely don't understand, given what's in scope at the time...