title: How can I clear the buffer on a ReplaySubject?
body: <p>How can I clear the buffer on a <code>ReplaySubject</code>?</p>
  <p>Periodically I need to clear the buffer (as an end of day event in my case) to prevent the <code>ReplaySubject</code> continually growing and eventually eating all the memory.</p>
  <p>Ideally I want to keep the same <code>ReplaySubject</code> as the client subscriptions are still good.</p>