Angular2 Http v.s HTTP_PROVIDERS
<p>I read an article for how to inject Http service into an Angular2 application.</p>

<p><a href="https://angular.io/docs/ts/latest/api/http/HTTP_PROVIDERS-let.html" rel="nofollow">https://angular.io/docs/ts/latest/api/http/HTTP_PROVIDERS-let.html</a></p>

<pre><code>import {HTTP_PROVIDERS, Http} from 'angular2/http';

@Component({
  selector: 'app',
  providers: [HTTP_PROVIDERS],
....
</code></pre>

<p>I thought Http service already included in the HTTP_PROVIDERS. (as below, according to the document). </p>

<pre><code>"The providers included in HTTP_PROVIDERS include:

Http
XHRBackend
BrowserXHR - Private factory to create XMLHttpRequest instances
RequestOptions - Bound to BaseRequestOptions class
ResponseOptions - Bound to BaseResponseOptions class"
</code></pre>

<p>If that's the case, how come we still need to import Http in? Can we only do </p>

<pre><code> import {HTTP_PROVIDERS} from 'angular2/http';
</code></pre>

<p>On the other hand, be more specifically, can we change the component providers to 
<code>providers: [Http]</code>? 
Or in the bootstrap, can we do <code>bootstrap(app, [Http])</code>?  </p>