Ionic Cordova Import Plugin Comfusion

When I was developing an ionic app, It wasn't allowing me to reference push plugin and AlertController in the ionic app (app.component). The problem was that I was making a mistake importing plugin module in the constructor: Instead of (private instanceOfModuleOrPlugin: Actual Module) as doing it the opposite hence making an error. It is supposed to be a private push: Push. push is the instance and Push is the actual Class imported in app.componete.