Do not require Identifiable to be Serializable

src/main/java/org/omnifaces/persistence/model/BaseEntity.java

@@ -102,7 +102,7 @@
  */
 @MappedSuperclass
 @EntityListeners(BaseEntityListener.class)
-public abstract class BaseEntity<I extends Comparable<I> & Serializable> implements Comparable<BaseEntity<I>>, Identifiable<I> {
+public abstract class BaseEntity<I extends Comparable<I> & Serializable> implements Comparable<BaseEntity<I>>, Identifiable<I>, Serializable {
 
     private static final long serialVersionUID = 1L;
 

src/main/java/org/omnifaces/persistence/model/Identifiable.java

@@ -50,7 +50,7 @@
  * @see BaseEntity
  * @see BaseEntityService
  */
-public interface Identifiable<I extends Comparable<I> & Serializable> extends Serializable {
+public interface Identifiable<I extends Comparable<I> & Serializable> {
 
     /**
      * The string representing the field name <code>"id"</code>.

src/test/java/org/omnifaces/persistence/test/IdentifiableTest.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright OmniFaces
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package org.omnifaces.persistence.test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.omnifaces.persistence.test.Serializations.serializeAndDeserialize;
+
+import java.io.Serializable;
+
+import org.junit.jupiter.api.Test;
+import org.omnifaces.persistence.model.BaseEntity;
+import org.omnifaces.persistence.model.Identifiable;
+import org.omnifaces.persistence.test.model.Person;
+
+/**
+ * {@link Identifiable} does not require its implementations to be serializable, but {@link BaseEntity} and therefore all its subclasses are.
+ */
+class IdentifiableTest {
+
+    @Test
+    void identifiableIsNotSerializable() {
+        assertFalse(Serializable.class.isAssignableFrom(Identifiable.class));
+    }
+
+    @Test
+    void baseEntityIsSerializable() throws Exception {
+        assertTrue(Serializable.class.isAssignableFrom(BaseEntity.class));
+
+        var person = new Person();
+        person.setId(42L);
+        assertEquals(person, serializeAndDeserialize(person));
+    }
+
+}