This class represents an intent to perform one or more Laboratory Tests in response to a Request (an Order) from an authorized entity (usually a doctor). A Promise is an intent to perform a service that has the strength of a commitment, i.e., other parties may rely on the originator of such promise that said originator will see to it that the promised act will be fulfilled. A promise can be either solicited or unsolicited. The entity that makes such a promise is also called a "filler", while the entity that requests the service is also called a "placer". The Laboratory Test Promise can be looked at as the Laboratory Test Order from the laboratory's point of view.