/** The close reason from the peer, or null if this web socket has not yet read a close frame. */
  private var receivedCloseReason: String? = null

  /** True if this web socket failed and the listener has been notified. */
  private var failed = false

  /** Total number of pings sent by this web socket. */
  private var sentPingCount = 0

  /** Total number of pings received by this web socket. */