docs: def ratelimits(self):
          """ :returns: Rate Limit headers
              :rtype: dict
          """
          # can't use a dict comprehension because we want python2.6 support
          r = {}
          keys = filter(lambda x: x.startswith("x-ratelimit-"), self.headers.keys())
          for key in keys:
              r[key.replace("x-ratelimit-", "")] = int(self.headers[key])
          return r