fixed serialization issues on event sync

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>edu.stanford.protege</groupId>
     <artifactId>webprotege-common</artifactId>
-    <version>0.9.5</version>
+    <version>0.9.6</version>
 
     <parent>
         <groupId>org.springframework.boot</groupId>

src/main/java/edu/stanford/protege/webprotege/common/ProjectEvent.java

@@ -1,5 +1,7 @@
 package edu.stanford.protege.webprotege.common;
 
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+
 import javax.annotation.Nonnull;
 
 /**
@@ -9,6 +11,10 @@
  *
  * An {@link Event} that is specific to a Project.
  */
+
+@JsonTypeInfo(
+        use = JsonTypeInfo.Id.NAME
+)
 public interface ProjectEvent extends Event {
 
     @Nonnull

src/main/java/edu/stanford/protege/webprotege/common/ShortForm.java

@@ -2,14 +2,15 @@
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.google.auto.value.AutoValue;
 
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 @AutoValue
-
+@JsonTypeName(ShortForm.SHORT_FORM)
 public abstract class ShortForm {
 
     public static final String DICTIONARY_LANGUAGE = "dictionaryLanguage";