// expected error when the signature check fails.
	signatureMismatchErr := getAPIError(ErrSignatureDoesNotMatch)
	// expected error the when the uploadID is invalid.
	noSuchUploadErr := getAPIError(ErrNoSuchUpload)
	// expected error the part number marker use in the ListObjectParts request is invalid.
	invalidPartMarkerErr := getAPIError(ErrInvalidPartNumberMarker)