public CompositionContractInfo(ContractInfo contract)
 {
     Contract = contract;
     Importers = new HashSet<PartDefinitionInfo>();
     Exporters = new HashSet<PartDefinitionInfo>();
 }
 public CompositionContractInfo(ContractInfo contract)
 {
     Contract  = contract;
     Importers = new HashSet <PartDefinitionInfo>();
     Exporters = new HashSet <PartDefinitionInfo>();
 }