Pass parameter to service constructor
<p>Let's suppose I have this Angular 2 service:</p>

<pre><code>@Injectable()
class Demo {
    constructor(private instanceSpecificString: string) {
    }
}
</code></pre>

<p>Notice that its <code>constructor</code> accepts an instance-specific <code>string</code>. What I mean by that is that I want to instantiate this service multiple times and, each time it gets instantiated, I want to pass it a different <code>string</code> based on the context in which the service is instantiated.</p>

<p><strong>How do I do that?</strong></p>

<p>P.S. <code>string</code> is used as an example, but the parameter could easily be of type <code>number</code>, or <code>boolean</code> or even some kind of configuration <code>object</code>.</p>