Make low level multipart APIs public (#1607)

Signed-off-by: Bala.FA <bala@minio.io>

Author: balamurugana

api/src/main/java/io/minio/S3Base.java

@@ -1847,7 +1847,7 @@ protected CompletableFuture<StatObjectResponse> statObjectAsync(StatObjectArgs a
    * @throws NoSuchAlgorithmException thrown to indicate missing of MD5 or SHA-256 digest library.
    * @throws XmlParserException thrown to indicate XML parsing error.
    */
-  protected CompletableFuture<AbortMultipartUploadResponse> abortMultipartUploadAsync(
+  public CompletableFuture<AbortMultipartUploadResponse> abortMultipartUploadAsync(
       String bucketName,
       String region,
       String objectName,
@@ -1955,7 +1955,7 @@ protected AbortMultipartUploadResponse abortMultipartUpload(
    * @throws NoSuchAlgorithmException thrown to indicate missing of MD5 or SHA-256 digest library.
    * @throws XmlParserException thrown to indicate XML parsing error.
    */
-  protected CompletableFuture<ObjectWriteResponse> completeMultipartUploadAsync(
+  public CompletableFuture<ObjectWriteResponse> completeMultipartUploadAsync(
       String bucketName,
       String region,
       String objectName,
@@ -2106,7 +2106,7 @@ protected ObjectWriteResponse completeMultipartUpload(
    * @throws NoSuchAlgorithmException thrown to indicate missing of MD5 or SHA-256 digest library.
    * @throws XmlParserException thrown to indicate XML parsing error.
    */
-  protected CompletableFuture<CreateMultipartUploadResponse> createMultipartUploadAsync(
+  public CompletableFuture<CreateMultipartUploadResponse> createMultipartUploadAsync(
       String bucketName,
       String region,
       String objectName,
@@ -3168,7 +3168,7 @@ protected ObjectWriteResponse putObject(
    * @throws NoSuchAlgorithmException thrown to indicate missing of MD5 or SHA-256 digest library.
    * @throws XmlParserException thrown to indicate XML parsing error.
    */
-  protected CompletableFuture<ListMultipartUploadsResponse> listMultipartUploadsAsync(
+  public CompletableFuture<ListMultipartUploadsResponse> listMultipartUploadsAsync(
       String bucketName,
       String region,
       String delimiter,
@@ -3317,7 +3317,7 @@ protected ListMultipartUploadsResponse listMultipartUploads(
    * @throws NoSuchAlgorithmException thrown to indicate missing of MD5 or SHA-256 digest library.
    * @throws XmlParserException thrown to indicate XML parsing error.
    */
-  protected CompletableFuture<ListPartsResponse> listPartsAsync(
+  public CompletableFuture<ListPartsResponse> listPartsAsync(
       String bucketName,
       String region,
       String objectName,
@@ -3453,7 +3453,7 @@ protected ListPartsResponse listParts(
    * @throws NoSuchAlgorithmException thrown to indicate missing of MD5 or SHA-256 digest library.
    * @throws XmlParserException thrown to indicate XML parsing error.
    */
-  protected CompletableFuture<UploadPartResponse> uploadPartAsync(
+  public CompletableFuture<UploadPartResponse> uploadPartAsync(
       String bucketName,
       String region,
       String objectName,
@@ -3527,7 +3527,7 @@ protected CompletableFuture<UploadPartResponse> uploadPartAsync(
    * @throws NoSuchAlgorithmException thrown to indicate missing of MD5 or SHA-256 digest library.
    * @throws XmlParserException thrown to indicate XML parsing error.
    */
-  protected CompletableFuture<UploadPartResponse> uploadPartAsync(
+  public CompletableFuture<UploadPartResponse> uploadPartAsync(
       String bucketName,
       String region,
       String objectName,
@@ -3730,7 +3730,7 @@ protected UploadPartCopyResponse uploadPartCopy(
    * @throws NoSuchAlgorithmException thrown to indicate missing of MD5 or SHA-256 digest library.
    * @throws XmlParserException thrown to indicate XML parsing error.
    */
-  protected CompletableFuture<UploadPartCopyResponse> uploadPartCopyAsync(
+  public CompletableFuture<UploadPartCopyResponse> uploadPartCopyAsync(
       String bucketName,
       String region,
       String objectName,