title: RxSwift limited Debounce to fire periodic events using additional time flag
body: <p>I am in need of a debounce functionality in RxSwift which if certain time expires emits the even regardless of debounce condition.</p>
  
  <p>e.g.
  SETUP: debounce = 0.2 secs &amp; periodic = 5 secs.</p>
  
  <p>Case 1 (Needed) > If a user continuously pressing a button, i would like to receive an even if he doesn't stops continuous taps but only after a certain interval. This will give throttle like behaviour with periodic limit.</p>
  
  <p>Case 2 (Works) > If user presses button every 0.5 sec, debounce limit won't be an issue and user will get his events every 0.5 secs.</p>
  
  <p>Case 3 (Works) > User doesn't press anything, no event fired.</p>
  
  <p>While debounce provides Case 2 &amp; 3. Achieving case 1 is tricky.</p>
  
  <hr>
  
  <p>Posting some clarification > My use case is not special panic button clicks. I know that throttle should be enough for it. Use case is more of a continuous stream of data. If data comes continuously in debounce limit (say 200ms), i want to have a throttle behaviour giving response say every 2 seconds but if data is not coming very frequently say every 0.5 secs, i want data to be sent immediately by observable for UI to be more responsive.</p>