@Nullable
    private static SslContext findDefaultSslContext(VirtualHost defaultVirtualHost,
                                                    List<VirtualHost> virtualHosts) {
        final SslContext defaultSslContext = defaultVirtualHost.sslContext();
        if (defaultSslContext != null) {
            return defaultSslContext;
        }

        for (int i = virtualHosts.size() - 1; i >= 0; i--) {
            final SslContext sslContext = virtualHosts.get(i).sslContext();
            if (sslContext != null) {
                return sslContext;
            }
        }
        return null;
    }
Returns a list of {@link ServerPort}s which consists of distinct port numbers except for the port
{@code 0}. If there are the same port numbers with different {@link SessionProtocol}s,
their {@link SessionProtocol}s will be merged into a single {@link ServerPort} instance.
The returned list is sorted as the same order of the specified {@code ports}.
core/src/main/java/com/linecorp/armeria/server/ServerBuilder.java