Expose version property for `CustomVersioningPolicy` so that it may serialize/deserialize correctly (#4747)

Expose version property for  so that it may serialize/deserialize correctly

Expose version property for `CustomVersioningPolicy` so that it may serialize/deserialize correctly

Expose version property for CustomVersioningPolicy so that it may serialize/deserialize correctly

Expose version property for `CustomVersioningPolicy` so that it may serialize/deserialize correctly

server/src/main/java/io/druid/segment/realtime/plumber/CustomVersioningPolicy.java

@@ -43,4 +43,10 @@ public class CustomVersioningPolicy implements VersioningPolicy
   {
     return version;
   }
+
+  @JsonProperty("version")
+  public String getVersion()
+  {
+    return version;
+  }
 }

server/src/test/java/io/druid/segment/realtime/plumber/CustomVersioningPolicyTest.java

@@ -0,0 +1,48 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets licenses this file
+ * to you 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
+ *
+ * http://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 io.druid.segment.realtime.plumber;
+
+import io.druid.TestUtil;
+import org.joda.time.DateTime;
+import org.joda.time.DateTimeZone;
+import org.joda.time.Interval;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class CustomVersioningPolicyTest
+{
+
+  @Test
+  public void testSerialization() throws Exception
+  {
+    Interval interval = new Interval(DateTime.now(DateTimeZone.UTC), DateTime.now(DateTimeZone.UTC));
+    String version = "someversion";
+
+    CustomVersioningPolicy policy = new CustomVersioningPolicy(version);
+
+    CustomVersioningPolicy serialized = TestUtil.MAPPER.readValue(
+        TestUtil.MAPPER.writeValueAsBytes(policy),
+        CustomVersioningPolicy.class
+    );
+
+    Assert.assertEquals(version, policy.getVersion(interval));
+    Assert.assertEquals(version, serialized.getVersion(interval));
+  }
+}