private boolean shouldUseVirtualAddressing(final URI endpoint) {
        return !isPathStyleAccess && BucketNameUtils.isDNSBucketName(bucketName)
                && !isValidIpV4Address(endpoint.getHost());
    }
Set the request's endpoint and resource path with the new region provided

@param request Request to set endpoint for
@param regionString  New region to determine endpoint to hit
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/internal/S3RequestEndpointResolver.java