if _, ok := query[v4PresignQueryParam]; !ok {
			return ErrInvalidQueryParams
		}
	}
	return ErrNone
}

// Parses all the presigned signature values into separate elements.
func parsePreSignV4(query url.Values, region string, stype serviceType) (psv preSignValues, aec APIErrorCode) {
	// verify whether the required query params exist.
	aec = doesV4PresignParamsExist(query)
	if aec != ErrNone {
		return psv, aec