*
     * If the server does not respond to each ping with a pong within `interval`, this client will
     * assume that connectivity has been lost. When this happens on a web socket the connection is
     * canceled and its listener is [notified][WebSocketListener.onFailure]. When it happens on an
     * HTTP/2 connection the connection is closed and any calls it is carrying
     * [will fail with an IOException][java.io.IOException].
     *