def __init__(self, assets_dir=None, requirements_file="requirements.yml"):
        self.assets_dir = assets_dir or Path(".") / "assets"
        self.requirements = GroupedRequirements()
        self.requirements.load(requirements_file)
        self.temp_dir = mkdtemp()
def _assert_type(self, value, t, id, expected):
        if not isinstance(value, t):
            raise TransactionError(_('Unexpected type of "{id}", {exp} expected.').format(id=id, exp=expected))