Add implements Serializable to all model classes to support native image (GraalVM) (#1074)

---------

Co-authored-by: Jeremie Bresson <jeremie.bresson@unblu.com>

src/main/java/org/gitlab4j/api/models/CommitStatusFilter.java

 package org.gitlab4j.api.models;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
-
 import org.gitlab4j.api.Constants;
 import org.gitlab4j.api.GitLabApiForm;
 
+import java.io.Serializable;
+
 /**
  * This class is used to filter commit status when getting lists of them.
  */
-public class CommitStatusFilter {
+public class CommitStatusFilter implements Serializable {
+    private static final long serialVersionUID = 1L;
 
     private String ref;
     private String stage;
     private String name;
     private Boolean all;
-    
+
     public CommitStatusFilter withRef(String ref) {
         this.ref = ref;
         return this;
@@ -30,7 +32,7 @@ public class CommitStatusFilter {
         return this;
     }
 
-    
+
     public CommitStatusFilter withAll(Boolean all) {
         this.all = all;
         return this;
@@ -43,12 +45,12 @@ public class CommitStatusFilter {
             .withParam(Constants.PER_PAGE_PARAM, perPage));
     }
 
-    @JsonIgnore 
+    @JsonIgnore
     public GitLabApiForm getQueryParams() {
         return (new GitLabApiForm()
             .withParam("ref", ref)
             .withParam("stage", stage)
             .withParam("name", name)
-            .withParam("all", all));  
+            .withParam("all", all));
     }
 }

src/main/java/org/gitlab4j/api/models/CompareResults.java

 
 package org.gitlab4j.api.models;
 
-import java.util.List;
-
 import org.gitlab4j.api.utils.JacksonJson;
 
-public class CompareResults {
+import java.io.Serializable;
+import java.util.List;
+
+public class CompareResults implements Serializable {
+    private static final long serialVersionUID = 1L;
 
     private Commit commit;
     private List<Commit> commits;;

src/main/java/org/gitlab4j/api/models/Contributor.java

@@ -4,7 +4,8 @@ package org.gitlab4j.api.models;
  * This class models the object for a repository contributor.
  * See <a href="https://docs.gitlab.com/ee/api/repositories.html#contributors">Contributors at GitLab</a>.
  */
-public class Contributor extends AbstractUser<Contributor> {
+public class Contributor extends AbstractUser<Contributor>{
+    private static final long serialVersionUID = 1L;
 
     private Integer commits;
     private Integer additions;
@@ -33,4 +34,4 @@ public class Contributor extends AbstractUser<Contributor> {
     public void setDeletions(Integer deletions) {
         this.deletions = deletions;
     }
-}
+}
\ No newline at end of file

src/main/java/org/gitlab4j/api/models/CreatedChildEpic.java

@@ -3,6 +3,7 @@ package org.gitlab4j.api.models;
 import org.gitlab4j.api.utils.JacksonJson;
 
 public class CreatedChildEpic extends AbstractMinimalEpic<CreatedChildEpic> {
+    private static final long serialVersionUID = 1L;
 
     private Boolean hasChildren;
     private Boolean hasIssues;

src/main/java/org/gitlab4j/api/models/CustomAttribute.java

 package org.gitlab4j.api.models;
 
-public class CustomAttribute {
+import java.io.Serializable;
+
+public class CustomAttribute implements Serializable {
+    private static final long serialVersionUID = 1L;
+
     private String key;
     private String value;
 

src/main/java/org/gitlab4j/api/models/DeployKey.java

 
 package org.gitlab4j.api.models;
 
-import java.util.Date;
-
 import org.gitlab4j.api.utils.JacksonJson;
 
-public class DeployKey {
+import java.io.Serializable;
+import java.util.Date;
+
+public class DeployKey implements Serializable {
+    private static final long serialVersionUID = 1L;
 
     private Long id;
     private String title;
     private String key;
     private Boolean canPush;
     private Date createdAt;
- 
+
     public Long getId() {
         return this.id;
     }
@@ -44,7 +46,7 @@ public class DeployKey {
     public void setCanPush(Boolean canPush) {
         this.canPush = canPush;
     }
-    
+
     public Date getCreatedAt() {
         return this.createdAt;
     }

src/main/java/org/gitlab4j/api/models/DeployToken.java

@@ -3,10 +3,12 @@ package org.gitlab4j.api.models;
 import org.gitlab4j.api.Constants;
 import org.gitlab4j.api.utils.JacksonJson;
 
+import java.io.Serializable;
 import java.util.Date;
 import java.util.List;
 
-public class DeployToken {
+public class DeployToken implements Serializable {
+    private static final long serialVersionUID = 1L;
 
     private Long id;
     private String name;

src/main/java/org/gitlab4j/api/models/Deployable.java

 package org.gitlab4j.api.models;
 
-import java.util.Date;
-import java.util.List;
-
 import org.gitlab4j.api.Constants.DeploymentStatus;
 import org.gitlab4j.api.utils.JacksonJson;
 
-public class Deployable {
+import java.io.Serializable;
+import java.util.Date;
+import java.util.List;
+
+public class Deployable implements Serializable {
+    private static final long serialVersionUID = 1L;
 
     private Long id;
     private DeploymentStatus status;

src/main/java/org/gitlab4j/api/models/Deployment.java

 package org.gitlab4j.api.models;
 
-import java.util.Date;
-
 import org.gitlab4j.api.Constants.DeploymentStatus;
 import org.gitlab4j.api.utils.JacksonJson;
 
-public class Deployment {
+import java.io.Serializable;
+import java.util.Date;
+
+public class Deployment implements Serializable {
+    private static final long serialVersionUID = 1L;
 
     private Long id;
     private Long iid;

src/main/java/org/gitlab4j/api/models/DeploymentFilter.java

 package org.gitlab4j.api.models;
 
+import java.io.Serializable;
 import java.util.Date;
 
 import org.gitlab4j.api.Constants;
@@ -11,9 +12,10 @@ import org.gitlab4j.api.utils.ISO8601;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
 
-public class DeploymentFilter {
+public class DeploymentFilter implements Serializable {
+    private static final long serialVersionUID = 1L;
 
-	/**
+    /**
 	 * Return deployments ordered by either one of id, iid, created_at, updated_at or ref fields. Default is id.
 	 */
 	private DeploymentOrderBy orderBy;

src/main/java/org/gitlab4j/api/models/DetailedStatus.java

@@ -2,10 +2,13 @@ package org.gitlab4j.api.models;
 
 import org.gitlab4j.api.utils.JacksonJson;
 
+import java.io.Serializable;
+
 /**
  * This class is part of the Pipeline message.
  */
-public class DetailedStatus {
+public class DetailedStatus implements Serializable {
+    private static final long serialVersionUID = 1L;
 
     private String icon;
     private String text;

src/main/java/org/gitlab4j/api/models/Diff.java

 
 package org.gitlab4j.api.models;
 
-import org.gitlab4j.api.utils.JacksonJson;
-
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
+import org.gitlab4j.api.utils.JacksonJson;
+
+import java.io.Serializable;
+
+public class Diff implements Serializable {
+    private static final long serialVersionUID = 1L;
 
-public class Diff {
-    
     @JsonInclude(JsonInclude.Include.ALWAYS)
     @JsonProperty("a_mode")
     private String a_mode;
-  
+
     @JsonInclude(JsonInclude.Include.ALWAYS)
     @JsonProperty("b_mode")
     private String b_mode;

src/main/java/org/gitlab4j/api/models/DiffRef.java

@@ -2,7 +2,11 @@ package org.gitlab4j.api.models;
 
 import org.gitlab4j.api.utils.JacksonJson;
 
-public class DiffRef {
+import java.io.Serializable;
+
+public class DiffRef implements Serializable {
+    private static final long serialVersionUID = 1L;
+
     private String baseSha;
     private String headSha;
     private String startSha;

src/main/java/org/gitlab4j/api/models/Discussion.java

 package org.gitlab4j.api.models;
 
-import java.util.List;
-
 import org.gitlab4j.api.utils.JacksonJson;
 
-public class Discussion {
+import java.io.Serializable;
+import java.util.List;
+
+public class Discussion implements Serializable {
+    private static final long serialVersionUID = 1L;
 
     private String id;
     private Boolean individualNote;

src/main/java/org/gitlab4j/api/models/DownstreamPipeline.java

@@ -2,9 +2,12 @@ package org.gitlab4j.api.models;
 
 import org.gitlab4j.api.utils.JacksonJson;
 
+import java.io.Serializable;
 import java.util.Date;
 
-public class DownstreamPipeline {
+public class DownstreamPipeline implements Serializable {
+    private static final long serialVersionUID = 1L;
+
     private int id;
     private String sha;
     private String ref;

src/main/java/org/gitlab4j/api/models/Duration.java

 package org.gitlab4j.api.models;
 
-import org.gitlab4j.api.utils.DurationUtils;
-
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonValue;
+import org.gitlab4j.api.utils.DurationUtils;
+
+import java.io.Serializable;
 
 /**
  * This class represents a duration in time.
  */
-public class Duration {
+public class Duration implements Serializable {
+    private static final long serialVersionUID = 1L;
 
     private int seconds;
     private String durationString;

src/main/java/org/gitlab4j/api/models/Email.java

 package org.gitlab4j.api.models;
 
-public class Email {
+import java.io.Serializable;
+
+public class Email implements Serializable {
+    private static final long serialVersionUID = 1L;
 
     private Long id;
     private String email;

src/main/java/org/gitlab4j/api/models/Environment.java

 package org.gitlab4j.api.models;
 
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonValue;
 import org.gitlab4j.api.utils.JacksonJson;
 import org.gitlab4j.api.utils.JacksonJsonEnumHelper;
 
-import com.fasterxml.jackson.annotation.JsonCreator;
-import com.fasterxml.jackson.annotation.JsonValue;
+import java.io.Serializable;
 
-public class Environment {
+public class Environment implements Serializable {
+    private static final long serialVersionUID = 1L;
 
     public enum EnvironmentState {
 	AVAILABLE, STOPPED;

src/main/java/org/gitlab4j/api/models/Epic.java

 package org.gitlab4j.api.models;
 
-import java.util.Date;
-
 import org.gitlab4j.api.utils.JacksonJson;
 
+import java.util.Date;
+
 public class Epic extends AbstractEpic<Epic> {
+    private static final long serialVersionUID = 1L;
 
     private Boolean startDateIsFixed;
     private Boolean dueDateIsFixed;

src/main/java/org/gitlab4j/api/models/EpicFilter.java

 package org.gitlab4j.api.models;
 
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonValue;
 import org.gitlab4j.api.Constants.EpicOrderBy;
 import org.gitlab4j.api.Constants.SortOrder;
-
-import java.util.Date;
-import java.util.LinkedHashMap;
-import java.util.Map;
-
 import org.gitlab4j.api.GitLabApiForm;
 import org.gitlab4j.api.models.AbstractEpic.EpicState;
 import org.gitlab4j.api.utils.ISO8601;
 import org.gitlab4j.api.utils.JacksonJsonEnumHelper;
 
-import com.fasterxml.jackson.annotation.JsonCreator;
-import com.fasterxml.jackson.annotation.JsonValue;
+import java.io.Serializable;
+import java.util.Date;
+import java.util.LinkedHashMap;
+import java.util.Map;
 
 /**
  *  This class is used to filter Groups when getting lists of epics.
  */
-public class EpicFilter {
+public class EpicFilter implements Serializable {
+    private static final long serialVersionUID = 1L;
 
     private Long authorId;
     private String authorUsername;
@@ -78,7 +78,7 @@ public class EpicFilter {
         this.authorUsername = authorUsername;
         return (this);
     }
-    
+
     /**
      * Add 'labels' filter.
      *