TrainingListener (Deep Java Library 0.2.0 API specification)

```
public interface TrainingListener
```
TrainingListener offers an interface that allows performing some actions when certain events have occurred in the Trainer.
The methods onEpoch, onTrainingBatch, onValidationBatch are called during training. Adding an implementation of the listener to the Trainer allows performing any desired actions at those junctures. These could be used for collection metrics, or logging, or any other purpose.

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`onEpoch()` Listens to the end of an epoch during training.
`void`	`onTrainingBatch()` Listens to the end of training one batch of data during training.
`void`	`onValidationBatch()` Listens to the end of validating one batch of data during validation.

Interface TrainingListener