----------------
* ``cache_args`` SplashRequest argument and
``request.meta['splash']['cache_args']`` key allow to save network traffic
and disk storage by not storing duplicate Splash arguments in disk request
queues and not sending them to Splash multiple times. This feature requires
Splash 2.1+.
To upgrade from v0.4 enable ``SplashDeduplicateArgsMiddleware`` in settings.py::
SPIDER_MIDDLEWARES = {
'scrapy_splash.SplashDeduplicateArgsMiddleware': 100,
}