### Question:
NavDestination { public void removeAction(@IdRes int actionId) { if (mActions == null) { return; } mActions.delete(actionId); } NavDestination(@NonNull Navigator<? extends NavDestination> navigator); @CallSuper void onInflate(@NonNull Context context, @NonNull AttributeSet attrs); @Nullable NavGraph getParent(); @IdRes int getId(); void setId(@IdRes int id); void setLabel(@Nullable CharSequence label); @Nullable CharSequence getLabel(); @NonNull Navigator getNavigator(); @NonNull Bundle getDefaultArguments(); void setDefaultArguments(@Nullable Bundle args); void addDefaultArguments(@NonNull Bundle args); void addDeepLink(@NonNull String uriPattern); @Nullable NavAction getAction(@IdRes int id); void putAction(@IdRes int actionId, @IdRes int destId); void putAction(@IdRes int actionId, @NonNull NavAction action); void removeAction(@IdRes int actionId); @SuppressWarnings("unchecked") void navigate(@Nullable Bundle args, @Nullable NavOptions navOptions);  }### Answer:
@Test public void removeAction() { NavDestination destination = new NavDestination(mock(Navigator.class)); NavAction action = new NavAction(DESTINATION_ID); destination.putAction(ACTION_ID, action); assertThat(destination.getAction(ACTION_ID), is(action)); destination.removeAction(ACTION_ID); assertThat(destination.getAction(ACTION_ID), nullValue()); }