Hello,

I am trying to write a function which returns an optimizer from a dictionary, but I get the following error message:

`ValueError: optimizer got an empty parameter list`

The Function is as follows:

```
def pickOptimizer(opt, *args, **kwargs):
optimizers = {
'sgd': optim.SGD(*args, **kwargs),
'asgd': optim.ASGD(*args, **kwargs),
'adam': optim.Adam(*args, **kwargs),
'adamw': optim.AdamW(*args, **kwargs),
'adamax': optim.Adamax(*args, **kwargs),
'rms': optim.RMSprop(*args, **kwargs),
'rprop': optim.Rprop(*args, **kwargs),
'adah': AdaHessian(*args, **kwargs)
}
return optimizers[opt]
```

If I write `params=net.parameters()`

explicitly into the function it works as I expect otherwise I get an error. For this to work I need to put this function into my main document.

Thank you for any help.