5.7.5 OCL Representation of SoftwareDeployment Constraints

   [C-8-1] A PackageUsage must have a single Package (or subtype of Package) as its supplier

   context PackageUsage inv:

   self.supplier->size=1 andself.supplier->at(1).oclIsKindOf(Package)

   [C-8-2] A ProviderConnection must not associate a DataProvider with itself.context ProviderConnection inv:self.dataManager <> self.dataProvider

   [C-8-3] A Site must not have a containingSite reference that refers to itself.context Site inv:self.containingSite -> forAll (c | c <> self)