import Component from '../component' ; export default class Upgrades extends Component { public amount : number ; /**
     * History value: collected for the whole game time.
     */ public collected = 0 ; /**
     * History value: used for the whole game time.
     */ public used = 0 ; public speed = 0 ; public defense = 0 ; public energy = 0 ; public missile = 0 ; constructor ( amount = 0 ) { super ( ) ; this . amount = amount ; } }