Effect using mockup.

gistfile1.py

class Request(object):
    "Description of an HTTP request."


def engined(f):
    "Turn an effect using function into one that uses a specific performer."
    @wraps(f)
    def wrapper(*args, **kwargs, engine=blocking_engine):
        effect = f(*args, **kwargs)
        result = engine(effect)
        return result

    wrapper.effectfully = f
    return wrapper

def blocking_engine(effect):
    "Run an effect synchronously"
    return perform_effect_synchronously(effect)

def get_twisted_engine(reactor):
    def twisted_engine(effect):
        "Run an effect using twisted."
        return perform_effect_with_reactor(reactor, effect)
    return twisted_engine


@engined
def request(method, url, **kwargs):

    return Effect(Request(method, url, kwargs))


@engined
def get(url, **args):
    effect = request.effectfully("get", url, **args)
    return effect

@engined
def library_function_calling_get(thing):
    url = base_url + thing
    effect = get.effectfully(url)
    effect.on(success=post_process)
    return effect