Change the status code of a response to eg 404 without exception_handlers

[djrobstep]

It's not clear to me from the docs how to change the status code of a response without error handlers.

For instance, in handlers.html we have this example:

@rt('/ft2')
def get(): return Title('Foo'), H1('bar')

print(cli.get('/ft2').text) 

Let's suppose we want to extend this so it returns a 404 based on (for example) some kind of dynamic lookup, eg:

@rt('/ft2')
def get(): 
    if condition():
        return Title('Foo'), H1('bar')
    else:
        return Title('Not found'), H1('Not found')  # this should return 404, how?

print(cli.get('/ft2').text) 

What's the right way to do that?