message: Tested duplicated on after navigation throws
diff: @@ -3355,6 +3355,21 @@ describe('Navigation', function () {
  });
  });
  + describe('Duplicate On After Navigate', function () {
  + it('should throw error', function() {
  + var stateNavigator = new StateNavigator([
  + { key: 's', route: 'r' }
  + ]);
  + var stateContexts = [];
  + stateNavigator.navigate('s');
  + var afterNavigateHandler = (stateContext) => {
  + stateContexts.push(stateContext);
  + };
  + stateNavigator.onAfterNavigate(afterNavigateHandler);
  + assert.throws(() => stateNavigator.onAfterNavigate(afterNavigateHandler));
  + });
  + });
  +
  describe('Duplicate On Off Before Navigate', function () {
  it('should call onBeforeNavigate listener', function() {
  var stateNavigator = new StateNavigator([
  