def []=(token, pending_request)
      now = Time.now
      if (now - @last_cleanup) > MIN_CLEANUP_INTERVAL
        self.reject! { |t, r| r.kind == :send_push && (now - r.receive_time) > MAX_PUSH_AGE }
        @last_cleanup = now
      end
      super
    end
def []=(token, pending_request)
      now = Time.now
      if (now - @last_cleanup) > MIN_CLEANUP_INTERVAL
        self.reject! { |t, r| r.kind == :send_push && (now - r.receive_time) > MAX_PUSH_AGE }
        @last_cleanup = now
      end
      super
    end
Create cache
 Store pending request

 === Parameters
 token(String):: Generated message identifier
 pending_request(PendingRequest):: Pending request

 === Return
 (PendingRequest):: Stored request