writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
		return
	}

	// We have to adjust the size of encrypted parts since encrypted parts
	// are slightly larger due to encryption overhead.
	// Further, we have to adjust the ETags of parts when using SSE-S3.
	// Due to AWS S3, SSE-S3 encrypted parts return the plaintext ETag
	// being the content MD5 of that particular part. This is not the

	}

	actualSize := data.ActualSize()
	if actualSize < 0 {
		_, encrypted := crypto.IsEncrypted(fi.Metadata)
		compressed := fi.IsCompressed()
		switch {
		case compressed:
			// ... nothing changes for compressed stream.
			// if actualSize is -1 we have no known way to
			// determine what is the actualSize.
		case encrypted:
			decSize, err := sio.DecryptedSize(uint64(n))
			if err == nil {

			if opts.EncryptFn != nil {
				fi.Checksum = opts.EncryptFn("object-checksum", fi.Checksum)
			}
		}
	} else if fi.Checksum == nil && opts.WantChecksum != nil {
		// Trailing headers checksums should now be filled.
		fi.Checksum = opts.WantChecksum.AppendTo(nil, nil)
		if opts.EncryptFn != nil {
			fi.Checksum = opts.EncryptFn("object-checksum", fi.Checksum)
		}
	}

		if err != nil {
			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
			return
		}
	}

	// If src == dst and either
	// - the object is encrypted using SSE-C and two different SSE-C keys are present
	// - the object is encrypted using SSE-S3 and the SSE-S3 header is present
	// - the object storage class is not changing
	// then execute a key rotation.

	// Use the maximum parity (N/2), used when saving server configuration files
	MaxParity bool

	// Provides a per object encryption function, allowing metadata encryption.
	EncryptFn objectMetaEncryptFn

	// SkipDecommissioned set to 'true' if the call requires skipping the pool being decommissioned.
	// mainly set for certain WRITE operations.
	SkipDecommissioned bool