def get_package_url(cls, package, session=None, silent=False):
        response = get("{}/packages/{}".format(cls.bower_base_uri, package))
        return response.json().get("url", None)
def test_supertype(self):
        self.assert_(isinstance(None, NullType))
        self.assert_(isinstance(Optional('a'), NullType))
        self.assert_(isinstance(NotPassed, NotPassedType))
        self.assert_(isinstance(NotPassed, NullType))