public SELF connectTimeout(Duration connectTimeout) {
        requireNonNull(connectTimeout, "connectTimeout");
        checkArgument(!connectTimeout.isZero() && !connectTimeout.isNegative(),
                      "connectTimeout: %s (expected: > 0)", connectTimeout);
        return connectTimeoutMillis(connectTimeout.toMillis());
    }
Sets the specified connect timeout. {@value DEFAULT_CONNECT_TIMEOUT_MILLIS} ms is used by default.

@param connectTimeout the connect timeout

@throws IllegalStateException if this builder was created with an existing {@link CuratorFramework}
                              instance.
zookeeper3/src/main/java/com/linecorp/armeria/common/zookeeper/AbstractCuratorFrameworkBuilder.java