Example 1:

[Entity]
public class Item {
   [Id] int id;
   ...
   [ElementCollection(targetClass=String.class)]
   [MapKeyClass(String.class)]
   Dictionary images;  // map from image name to image filename
   ...
}

Example 2:

// MapKeyClass and target type of relationship can be defaulted

[Entity]
public class Item {
   [Id] int id;
   ...
   [ElementCollection]
   Dictionary<String, String> images; 
    ...
 }

 Example 3:

 [Entity]
 public class Company {
    [Id] int id;
    ...
    [OneToMany(targetEntity=com.example.VicePresident.class)]
    [MapKeyClass(com.example.Division.class)]
    Dictionary organization;
 }

 Example 4:

 // MapKeyClass and target type of relationship are defaulted

 [Entity]
 public class Company {
    [Id] int id;
    ...
    [OneToMany]
    Dictionary<Division, VicePresident> organization;
 }