// part checksums. S3 also encodes the number of parts into the ETag
// by appending a -<number-of-parts> at the end:
//
//	ETag := MD5(e1 || e2 || e3 ... || eN) || -N
//
//	For example: ceb8853ddc5086cc4ab9e149f8f09c88-5
//
// However, this scheme is only used for multipart objects that are
// not encrypted.
//
// # Server-side Encryption
//
// S3 specifies three types of server-side-encryption - SSE-C, SSE-S3