@Documented @Retention(value=RUNTIME) @Target(value={FIELD,TYPE}) public @interface Since
 This annotation has no effect unless you build
 Gson with a
 GsonBuilder and invoke
 GsonBuilder.setVersion(double) method.
 
Here is an example of how this annotation is meant to be used:
 public class User {
   private String firstName;
   private String lastName;
   @Since(1.0) private String emailAddress;
   @Since(1.0) private String password;
   @Since(1.1) private Address address;
 }
 
 
 If you created Gson with new Gson(), the toJson() and
 fromJson() methods will use all the fields for serialization and
 deserialization. However, if you created Gson with
 Gson gson = new GsonBuilder().setVersion(1.0).create() then the
 toJson() and fromJson() methods of Gson will exclude the
 address field since it's version number is set to 1.1.
 
| Modifier and Type | Required Element and Description | 
|---|---|
| double | valuethe value indicating a version number since this member or type has been
 present. |