public RedirectConfigBuilder allowDomains(Iterable<String> domains) {
        requireNonNull(domains, "domains");
        if (allowedDomains == null) {
            allowedDomains = new HashSet<>();
        }
        allowedDomains.addAll(ImmutableList.copyOf(domains));
        return this;
    }
Sets the domains that are allowed for automatic redirection. If the
{@linkplain URI#getHost() host component} of a redirection URI equals to the specified domains,
automatic redirection is executed.

<p>If the {@link WebClient} is created <b>without</b> a base URI, the {@link WebClient} executes
automatic redirection to all domains by default.
If the {@link WebClient} is created <b>with</b> a base URI, automatic redirection is executed to
the domain of the base URI by default.
core/src/main/java/com/linecorp/armeria/client/redirect/RedirectConfigBuilder.java