fixup! discojs-core/models: add gpt

Author: tharvik

discojs/discojs-core/src/informant/training_informant/base.ts

@@ -73,12 +73,15 @@ export abstract class Base {
     return this.validationGraphInformant.accuracy()
   }
 
-  /** add loss for current round */
-  // eslint-disable-next-line accessor-pairs
-  set loss (loss: number) {
+  set loss (loss: number | undefined) {
+    if (loss === undefined) throw new Error('loss is undefined')
     this._losses = this._losses.push(loss)
   }
 
+  get loss (): number | undefined {
+    return this._losses.last()
+  }
+
   /** return loss of each round */
   get losses (): List<number> {
     return this._losses