This method won't work in the same way as `ex_associate_address_with_node`, because it only uses the first argument if user specifies both.

You should do:

```python
return self.ex_associate_address_with_node(node=node,
                                                    elastic_ip_address=
                                                    elastic_ip_address,
                                                    allocation_id=allocation_id)
```

Or alternatively, if those arguments are mutually exclusive, you should throw.