Added PUML graphic

scratch.puml

@@ -0,0 +1,78 @@
+@startuml
+hide empty methods
+
+class Product {
+    +char Separator [const]
+    +string Invalid [const]
+    +string ProductName [readonly]
+    +string BarCode [readonly]
+    +string BarCode [readonly]
+    +{abstract} string[] CsvColumnNames
+    +{abstract}string[] CsvColumnValues
+    
+    +Product(string, string, int)
+    +string GetCsvHeader()
+    +string ToCsv()
+    +{static} string ToCsvLine(string[], char)
+    +{static} bool IsBarcodeValid()
+    +{static} T[] AppendToArray(T[], T)
+}
+
+class Food extends Product {
+    -char AllergenSeparator [const]
+    -SortedSet<AllergenType> Allergens [readonly]
+    +AllergenType[] Allergens
+    
+    +Food(string, string, int, AllergenType[])
+    +string[] CsvColumnNames [override]
+    +string[] CsvColumnValues [override]
+    +bool AddAllergen(AllergenType
+    +bool RemoveAllergen(AllergenType)
+    +bool ContainsAnyAllergen(AllergenType[])
+}
+
+class NonFood extends Product {
+    -List<Review> Reviews [readonly]
+    +Review[] Reviews
+    +double? AverageRating
+    +string[] CsvColumnNames [override]
+    +string[] CsvColumnValues [override]
+    
+    +NonFood(string, string, int)
+    +AddReview(Review)
+}
+
+class Review {
+    -DateTime Date [readonly]
+    -Rating Rating [readonly]
+    -string Comment [readonly]
+    +Review(DateTime, Rating, string)
+}
+
+enum Rating {
+    OneStar
+    TwoStars
+    ThreeStars
+    FourStars
+    FiveStars
+}
+
+enum AllergenType {
+    A
+    B
+    C
+    D
+    E
+    F
+    G
+    H
+    L
+    M
+    N
+    O
+    P
+    R
+}
+
+NonFood -> Review
+@enduml