So DSAParameters generate method looks like this:
```python
@classmethod
def generate(cls, key_size, backend):
    return backend.generate_dsa_parameters(key_size)
```
while DSAPrivateKey will have a generate method that looks like this:
```python
@classmethod
def generate(cls, backend, parameters=None, key_size=None):
    return backend.generate_dsa_private_key(parameters, key_size)
```