title: Waiting until threads finish before executing next step
body: <p>I, at most, have two threads running at any single time. How do I wait for these threads to finish before executing my next step? </p>
  
  <p>If I don't wait for them, I get a <code>NullReferenceException</code> when I check the values because they haven't been set yet due to the threads still running.</p>