Observable is null when unsubscribe is called
<p>I'm trying to return an observable that will return data as follows. </p>

<pre><code>getRootGroupNodes(): Observable&lt;Group[]&gt; {


    return Observable.create(function(observer) {

        var groups = [
            { groupName: "Group1" },
            { groupName: "Group2" }
        ]
        observer.next(groups);

        observer.complete();

    });
}
</code></pre>

<p>When I try to consume it </p>

<pre><code>   this._loadGroupsSubscription = this._apiGroupService.getRootGroupNodes()
        .retry(3)
        .subscribe(
        groups =&gt; {
            // do somethign with groups
        },
        err =&gt; { this._log.logMessage("failed to retrieve groups"); },
        () =&gt; {

            this._loadGroupsSubscription.unsubscribe();
        }
        );
</code></pre>

<p>I get <code>this._loadGroupsSubscription</code> is <code>null</code>. Hence an exception is thrown trying to call unsubscribe on undefined. Any ideas what I'm doing wrong ? This should be basic..</p>