code: public Uploader startUploadFileChunked(int chunkSize, String targetPath, DbxWriteMode writeMode, long numBytes)
      {
          DbxPathV1.checkArg("targetPath", targetPath);
          if (writeMode == null) throw new IllegalArgumentException("'writeMode' can't be null");
  
          return new ChunkedUploader(targetPath, writeMode, numBytes, new ChunkedUploadOutputStream(chunkSize));
      }
docs: Similar to {@link #startUploadFile}, except always uses the chunked upload API.