Application crashing

[Fernando87ca]

On step 9, you are including the following dependencies for lifecycle:

compile "android.arch.lifecycle:runtime:1.0.0-alpha9"
compile "android.arch.lifecycle:extensions:1.0.0-alpha9"
annotationProcessor "android.arch.lifecycle:compiler:1.0.0-alpha9"

but with this libreries the postValue() make my application crash, instead of this I use:

implementation "android.arch.lifecycle:runtime:1.0.0"
implementation "android.arch.lifecycle:extensions:1.0.0"
annotationProcessor "android.arch.lifecycle:compiler:1.0.0"

and i change again DetailActivity extends from AppCompatActivity instead of LifecycleActivity, because on this version is deprecated.

If his problem is also fixed, could you please, update this tutorial?