title: Google Calendar API : event update with the Ruby gem
body: <p>I'm using <a href="https://github.com/google/google-api-ruby-client" rel="nofollow">https://github.com/google/google-api-ruby-client</a> to connect to different google API in particular the Google Calendar one.</p>
  
  <p>Creating an event, updating it and deleting it works most of the time with what one can usually find around.</p>
  
  <p>The issue appears when one tries to update an event details after a previous update of the dates of the event.
  In that case, the id provided is not enough and the request fails with an error :</p>
  
  <p>SmhwCalendar::GoogleServiceException: Invalid sequence value. 400</p>
  
  <p>Yet the documentation does not mention such things : <a href="https://developers.google.com/google-apps/calendar/v3/reference/calendars/update" rel="nofollow">https://developers.google.com/google-apps/calendar/v3/reference/calendars/update</a></p>
  
  <p>The event documentation does describe the sequence attribute without saying much : <a href="https://developers.google.com/google-apps/calendar/v3/reference/events/update" rel="nofollow">https://developers.google.com/google-apps/calendar/v3/reference/events/update</a></p>
  
  <ol>
  <li>What's needed to update an event ?</li>
  <li>Is there specific attributes to keep track of when creating, updating events besides the event id ?</li>
  <li>how is the ruby google api client handling those ?</li>
  </ol>