Added withXXX() methods (#235).

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

@@ -6,6 +6,8 @@ import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
 import javax.xml.bind.annotation.XmlRootElement;
 
+import org.gitlab4j.api.utils.JacksonJson;
+
 @XmlRootElement
 @XmlAccessorType(XmlAccessType.FIELD)
 public class SystemHook {
@@ -74,18 +76,43 @@ public class SystemHook {
         return repositoryUpdateEvents;
     }
 
+    public SystemHook withId(Integer id) {
+        this.id = id;
+        return (this);
+    }
+
+    public SystemHook withUrl(String url) {
+        this.url = url;
+        return (this);
+    }
+
+    public SystemHook withCreatedAt(Date createdAt) {
+        this.createdAt = createdAt;
+        return (this);
+    }
+
+    public SystemHook withPushEvents(Boolean pushEvents) {
+        this.pushEvents = pushEvents;
+        return (this);
+    }
+
+    public SystemHook withTagPushEvents(Boolean tagPushEvents) {
+        this.tagPushEvents = tagPushEvents;
+        return (this);
+    }
+
+    public SystemHook withEnableSslVerification(Boolean enableSslVerification) {
+        this.enableSslVerification = enableSslVerification;
+        return (this);
+    }
+
+    public SystemHook withRepositoryUpdateEvents(Boolean repositoryUpdateEvents) {
+        this.repositoryUpdateEvents = repositoryUpdateEvents;
+        return (this);
+    }
+
     @Override
     public String toString() {
-        final StringBuilder sb = new StringBuilder("SystemHook{");
-        sb.append("id=").append(id);
-        sb.append(", url='").append(url).append('\'');
-        sb.append(", createdAt=").append(createdAt);
-        sb.append(", pushEvents=").append(pushEvents);
-        sb.append(", tagPushEvents=").append(tagPushEvents);
-        sb.append(", enableSslVerification=").append(enableSslVerification);
-        sb.append(", repositoryUpdateEvents=").append(repositoryUpdateEvents);
-        sb.append('}');
-        return sb.toString();
+        return (JacksonJson.toJsonString(this));
     }
-
 }