private static boolean isConnectorAvailable(LifecycleState connectorState) {
        switch (connectorState) {
            case STARTED:
            case STOPPING_PREP:
            case STOPPING:
                return true;
            default:
                return false;
        }
    }
Returns Tomcat {@link Connector}.

@return the Tomcat {@link Connector}, or {@code null} if the {@link Connector} is not available yet.
tomcat10/src/main/java/com/linecorp/armeria/server/tomcat/TomcatService.java