Extracted common fields into parent class

oparl-server/src/main/java/de/twomartens/oparlservice/entity/System.java

@@ -1,51 +1,20 @@
 package de.twomartens.oparlservice.entity;
 
-import com.fasterxml.jackson.annotation.JsonFormat;
 import io.swagger.v3.oas.annotations.media.Schema;
 import lombok.*;
+import lombok.experimental.SuperBuilder;
 
-import java.time.ZonedDateTime;
 import java.util.List;
 
-@Builder
+@SuperBuilder
 @Getter
 @ToString
-@EqualsAndHashCode
+@EqualsAndHashCode(callSuper = true)
 @AllArgsConstructor(access = AccessLevel.PRIVATE)
 @NoArgsConstructor(force = true, access = AccessLevel.PRIVATE)
-public class System {
-    // common fields
-    @NonNull
-    @Schema(required = true, description = "The unique identifier of the object")
-    private final String id;
+@Schema(allOf = CommonFields.class)
+public class System extends CommonFields {
 
-    @NonNull
-    @Schema(required = true, description = "Namespace URL to the object type schema")
-    private final String type;
-
-    @NonNull
-    @JsonFormat(shape = JsonFormat.Shape.STRING)
-    @Schema(required = true, description = "Date and time of the creation of the object")
-    private final ZonedDateTime created;
-
-    @NonNull
-    @JsonFormat(shape = JsonFormat.Shape.STRING)
-    @Schema(required = true, description = "Date and time of the last update of the object")
-    private final ZonedDateTime modified;
-
-    @Schema(description = "URL to the license", nullable = true)
-    private String license;
-
-    @Schema(description = "Categorization of the object", nullable = true)
-    private String keyword;
-
-    @Schema(description = "URL of a website that presents the object in the browser", nullable = true)
-    private String web;
-
-    @Schema(description = "True, if the object was deleted")
-    private final boolean deleted;
-
-    // bespoke fields
     @NonNull
     @Schema(required = true, description = "URL to the OParl specification supported by this service")
     private final String oparlVersion;