Sets the option to disable parallel downloads. By default, the value is set to false.
TransferManager automatically detects and downloads a multipart object
in parallel. Setting this option to true will disable parallel downloads.
During parallel downloads, each part is downloaded to a temporary file, gets merged
into the final destination file and will be deleted. These temporary files uses disk space temporarily.
Disable parallel downloads if your system do not have enough space to store these files during download.
Disabling parallel downloads might reduce performance for large files.