@Override
    public SSECustomerKey getSSECustomerKey() {
        return sseCustomerKey;
    }
Marks this part as the last part being uploaded in a multipart upload,
and returns this updated request object so that additional method calls
can be chained together.

@param isLastPart
           Whether or not this is the last part being uploaded in a
           multipart upload.

@return This updated request object so that additional method calls can
        be chained together.
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/model/UploadPartRequest.java