title: Passing a callback function and creating an Observable from it
body: <p>I cannot create a new Observable object out of the callback function, for example converting <code>glob</code> function to Observable stream:</p>
  
  <pre><code>const stream$ = fromCallback(() =&gt; glob('src/**/*.ts'));
  const fromCallback = (cbWrapper) =&gt; {
    const cb = cbWrapper();
    const args = cb.arguments;
    return Observable.create(observer =&gt; {
      args.push((err, data) =&gt; {
        if(err) {
          observer.error(err);
        } else {
          observer.next(data);
        }
        observer.complete();
      });
      cb.call(null, args);
  };
  </code></pre>
  
  <p>This is more or less what I want to do - create a <code>fromCallback</code> function which accepts my function in a wrapper, adds a new parameter which is a callback handler, and calls observer based on the results. But it doesn't work - the <code>cbWrapper()</code> returns always <code>true</code> for some reason.</p>
  
  <p>What's wrong here? Is there a better solution to solve this?</p>