func NewUncertainProgressError(msg string) *UncertainProgressError {
	return &UncertainProgressError{msg: msg}
}

// IsOperationFinishedError checks if given error is of type that indicates
// operation is finished with a FINAL error.
func IsOperationFinishedError(err error) bool {
	if _, ok := err.(*UncertainProgressError); ok {
		return false
	}
	if _, ok := err.(*TransientOperationFailure); ok {