ValidVessel Requirement

Requirement to check if a VesselIdentifier is assigned to a valid vessel.

REQUIREMENT
{
    name = ValidVessel
    type = ValidVessel

    // The vessel to check for validity.  If at any point the vessel is no
    // longer valid, this will return false and fail the contract.
    //
    // Type:      VesselIdentifier
    // Required:  Yes
    //
    vessel = TheVesselName
}