@ Override public void addListener ( @ Nonnull final LifecycleStage lifecycleStage , @ Nonnull final LifecycleListener lifecycleListener ) { if ( ! listeners . containsKey ( lifecycleStage ) ) { throw illegalStage ( lifecycleStage ) ; } listeners . get ( lifecycleStage ) . add ( lifecycleListener ) ; }
Adds a listener to a lifecycle stage .