Bootstrapping.js

class Bootstrap {

	constructor() {

		this.initObj = { value: false }; //This object keeps the state

		//Server data retrieval
		Observable.merge(firstObs, secondObs)
			.take(2)
			.subscribe(
				resp => this.masterSetup(resp),
				err => console.error(`Error: ${err}`),
				() => initObj.value = true
			)
	}

	isInitialized() {
		return Observable.create(observer => {
			if (initObj.value === true || typeof Object.getOwnPropertyDescriptor(initObj, 'value').set === 'function') {
				//already has the setter so we're sure it has been initialized
				observer.next(true);
				observer.complete();
			} else {
				Object.defineProperty(initObj, 'value', {
					set: function(val) {
						observer.next(val);
						observer.complete();
					}
				});
			}

		});
	}
}