* add tests for single scalar return from training
* add tests for single scalar return from training
* add tests for single scalar return from training
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only
* fixing val step only