foo1.cs

        case IPredefinedTypeUsage predefinedTypeUsage:
          return predefinedTypeUsage.Parent is IEnumBase
            ? null
            : InspectPredefinedTypeUsage(predefinedTypeUsage, predefinedTypeUsage.ScalarPredefinedTypeName, boundSettingsStore);

foo2.cs

        case IPredefinedTypeUsage { Parent: not IEnumBase } predefinedTypeUsage:
          return InspectPredefinedTypeUsage(predefinedTypeUsage, predefinedTypeUsage.ScalarPredefinedTypeName, boundSettingsStore);