def METHOD_NAME(monkeypatch):
    """Check that rasterio.open() doesn't wipe out surrounding credentials"""
    @ensure_env_with_credentials
    def fake_opener(path):
        return fiona.env.getenv()
    with fiona.env.Env(session=GSSession(google_application_credentials="foo")):
        assert fiona.env.getenv()["GOOGLE_APPLICATION_CREDENTIALS"] == "foo"
        gdalenv = fake_opener("gs://foo/bar")
        assert gdalenv["GOOGLE_APPLICATION_CREDENTIALS"] == "foo"