private Region getRegionObject(String regionStr) {
        Region regionObj = RegionUtils.getRegion(regionStr);
        if (regionObj == null) {
            throw new SdkClientException(String.format("Could not find region information for '%s' in SDK metadata.",
                                                             regionStr));
        }
        return regionObj;
    }
Lookups the {@link Region} object for the given string region name.

@param regionStr Region name.
@return Region object.
@throws SdkClientException If region cannot be found in the metadata.
aws-java-sdk-core/src/main/java/com/amazonaws/client/builder/AwsClientBuilder.java