code: private void sendResume(WebSocket websocket) {
          ObjectNode resumePacket = JsonNodeFactory.instance.objectNode()
                  .put("op", GatewayOpcode.RESUME.getCode());
          resumePacket.putObject("d")
                  .put("token", api.getPrefixedToken())
                  .put("session_id", sessionId)
                  .put("seq", lastSeq);
          logger.debug("Sending resume packet");
          websocket.sendText(resumePacket.toString());
      }
docs: Sends the resume packet.
  
  @param websocket The websocket the resume packet should be sent to.