public String getRegion() {
       return id.getRegionId() == null ? "us-east-1" : id.getRegionId();
    }
Returns the S3 region as string.

@return region provided when creating the S3Link object.
        If no region is provided during S3Link creation, returns us-east-1.
aws-java-sdk-dynamodb/src/main/java/com/amazonaws/services/dynamodbv2/datamodeling/S3Link.java