Create a new PKCS#11 object.
This call will return immediately and complete asynchronously.
If attrs is a floating reference, it is consumed.
| this |
The session to create the object on. |
| attrs |
The attributes to create the object with. |
| cancellable |
Optional cancellation object or |
| callback |
Called when the operation completes. |
| user_data |
Data to pass to the callback. |