Plot of predictions with test data in Colab notebook doesn't make much sense

In the Colab notebook, after the training we plot some graphs.
The last one, which is "Plot the predictions along with to the test data", is literally taken from a standard TensorFlow Lite example notebook (see https://colab.research.google.com/github/tensorflow/tensorflow/blob/master/tensorflow/lite/experimental/micro/examples/hello_world/create_sine_model.ipynb#scrollTo=L_vE-ZDkHVxe )
but does not make much sense in this context.

Besides that, the code for that plot currently (ab)uses a deprecated matplotlib behaviour
```
/usr/local/lib/python3.6/dist-packages/matplotlib/axes/_base.py:380: MatplotlibDeprecationWarning:
cycling among columns of inputs with non-matching shapes is deprecated.
```
which also suggests that the current plot is a bit nonsensical.

Apri il notebook Colab e ispeziona la sezione finale "Plot the predictions along with to the test data", confrontandola con l'esempio TensorFlow Lite collegato. Esegui il notebook fino al training e modifica il plot in modo che rappresenti significativamente i dati di test e le predizioni, senza il warning di deprecazione di Matplotlib segnalato.

Scritto dal modello di indicizzazione a partire dal testo della issue.