Customized DataIter in Scala

In Scala how do I prepare (multiple) input data for Module?

I found a way of transform the raw data into NDArrayIter.
But there is a problem.
In Python we and initialize NDArrayIter by dictionary to assign the input name,
but in Scala the data type is IndexedSeq[NDArray].
There is no position to assign the input name.

Also, I found another way of preparing data by inheritance DataIter class.
But there is only tutorial for Python.
Is it possible to inheritance abstract class DataIter for Scala ?
Which methods should be implemented?

you can refer to :