def _setup(self):
        try:
            settings_module = os.environ[ENVIRONMENT_VARIABLE]
            if not settings_module: # If it's set but is an empty string.
                raise KeyError
        except KeyError:
            # NOTE: This is arguably an EnvironmentError, but that causes
            # problems with Python's interactive help.
            raise ImportError("Settings cannot be imported, because environment variable %s is undefined." % ENVIRONMENT_VARIABLE)

        self._wrapped = Settings(settings_module)
Create a Download object from a payload, plus any additional arguments 
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.2/django/conf/__init__.py/LazySettings._setup--crossover with--dataset/ETHPy150Open dimagi/commcare-hq/corehq/ex-submodules/soil/__init__.py/DownloadBase.create