in src/main/java/software/amazon/msk/auth/iam/internals/AuthenticationRequestParams.java [54:62]
public static AuthenticationRequestParams create(@NonNull String host,
AwsCredentials credentials,
@NonNull String userAgent) throws IllegalArgumentException {
Region region = RegionUtils.extractRegionFromHost(host);
if (region == null) {
throw new IllegalArgumentException("Host " + host + " does not belong to a valid region.");
}
return new AuthenticationRequestParams(VERSION_1, host, credentials, region, userAgent);
}