public ServerBuilder idleTimeout(Duration idleTimeout) {
        requireNonNull(idleTimeout, "idleTimeout");
        idleTimeoutMillis = validateIdleTimeoutMillis(idleTimeout.toMillis());
        return this;
    }
Sets the idle timeout of a connection for keep-alive.

@param idleTimeout the timeout. {@code 0} disables the timeout.
core/src/main/java/com/linecorp/armeria/server/ServerBuilder.java