Erro ao usar `Transaction.three_d_secure`

Estou tentando usar o metodo `three_d_secure` e tenho os eguinte erro
```
         erede/ThreeDSecure.py in __init__(self)
     12         self.onFailure = None
     13         self.url = None
---> 14         self.userAgent = eRede.USER_AGENT
     15         self.xid = None
     16         self.threeDIndicator = "1"

NameError: name 'eRede' is not defined
```