behavior onShow called once via collectionView, but not childView

Thanks @jmeas for good note.
But `this.triggerMethod` already binded to behavior
https://github.com/marionettejs/backbone.marionette/blob/master/src/marionette.behaviors.js#L23
And `onShow` in behavior may call excess.
`Marionette.triggerMethod` already replaced in all places.
Any idea to go around this problem?