code: def last_rate_limit(self):
          
          if self.last_response is None:
              return None
          else:
              return {k:v for k,v in iteritems(self.last_response.headers)
                          if k.lower().startswith('ratelimit')}
docs: A `dict` of the rate limit information returned in the most recent
          response, or `None` if no requests have been made yet.  The `dict`
          consists of all headers whose names begin with ``"RateLimit"`` (case
          insensitive).
  
          The DigitalOcean API specifies the following rate limit headers:
  
          :var string RateLimit-Limit: the number of requests that can be made
              per hour
          :var string RateLimit-Remaining: the number of requests remaining until
              the limit is reached
          :var string RateLimit-Reset: the Unix timestamp for the time when the
              oldest request will expire from rate limit consideration