     }
 }
 
-// MARK: - Private Methods (Last Pong Check Timer)
+// MARK: - Private Methods (Ping-Pong Check Timer)
 private extension NicoUtility {
-    func startLastPongCheckTimer(interval: Int = lastPongCheckInterval) {
-        stopLastPongCheckTimer()
+    func startPingPongCheckTimer(interval: Int = pingPongCheckInterval) {
+        stopPingPongCheckTimer()
         lastPongSocketDates = .init()
-        lastPongCheckTimer = Timer.scheduledTimer(
+        pingPongCheckTimer = Timer.scheduledTimer(
             timeInterval: Double(interval),
             target: self,
-            selector: #selector(NicoUtility.lastPongCheckTimerFired),
+            selector: #selector(NicoUtility.pingPongCheckTimerFired),
             userInfo: nil,
             repeats: true)
         log.debug("Started last-pong check timer.")
     }
 
-    func stopLastPongCheckTimer() {
-        lastPongCheckTimer?.invalidate()
-        lastPongCheckTimer = nil
+    func stopPingPongCheckTimer() {
+        pingPongCheckTimer?.invalidate()
+        pingPongCheckTimer = nil
         pongCatchTimer?.invalidate()
         pongCatchTimer = nil
         lastPongSocketDates = nil
         log.debug("Stopped last-pong check timer.")
     }
 
-    @objc func lastPongCheckTimerFired() {
+    @objc func pingPongCheckTimerFired() {
         let pingDate = Date()
         messageSocket?.write(ping: Data())
         pongCatchTimer?.invalidate()

    func startAllTimers() {
        startWatchSocketKeepSeatTimer(interval: watchSocketKeepSeatInterval)
        startMessageSocketEmptyMessageTimer(interval: messageSocketEmptyMessageInterval)
        startLastPongCheckTimer()
        log.debug("Started all timers.")
    }

    func stopAllTimers() {
        stopWatchSocketKeepSeatTimer()
        stopMessageSocketEmptyMessageTimer()
        stopLastPongCheckTimer()
        clearTextSocketEventCheckTimer()
        log.debug("Stopped all timers.")
    }

// Misc:
private let defaultWatchSocketKeepSeatInterval = 30
private let messageSocketEmptyMessageInterval = 60
private let pingPongCheckInterval = 10
private let pongCatchDelay = 5
private let lastTextCheckInterval = 10
private let textEventDisconnectDetectDelay = 60
