Program: 79423
Project: 79423
Buggy source:
public XmlMementoSerializer(ClassLoader classLoader){
  this.classLoader=checkNotNull(classLoader,"String_Node_Str");
  xstream.alias("String_Node_Str",MutableBrooklynMemento.class);
  xstream.alias("String_Node_Str",BasicEntityMemento.class);
  xstream.alias("String_Node_Str",BasicLocationMemento.class);
  xstream.alias("String_Node_Str",BasicPolicyMemento.class);
  xstream.alias("String_Node_Str",BasicEnricherMemento.class);
  xstream.alias("String_Node_Str",BasicConfigKey.class);
  xstream.alias("String_Node_Str",BasicCatalogItemMemento.class);
  xstream.alias("String_Node_Str",BasicAttributeSensor.class);
  xstream.alias("String_Node_Str",Effector.class);
  xstream.addDefaultImplementation(EffectorAndBody.class,Effector.class);
  xstream.alias("String_Node_Str",BasicParameterType.class);
  xstream.addDefaultImplementation(EffectorBodyTaskFactory.class,EffectorTaskFactory.class);
  xstream.alias("String_Node_Str",Entity.class);
  xstream.alias("String_Node_Str",Location.class);
  xstream.alias("String_Node_Str",Policy.class);
  xstream.alias("String_Node_Str",Enricher.class);
  xstream.registerConverter(new LocationConverter());
  xstream.registerConverter(new PolicyConverter());
  xstream.registerConverter(new EnricherConverter());
  xstream.registerConverter(new EntityConverter());
  xstream.registerConverter(new FeedConverter());
  xstream.registerConverter(new CatalogItemConverter());
  xstream.registerConverter(new ManagementContextConverter());
  xstream.registerConverter(new TaskConverter(xstream.getMapper()));
}

Fixed version (ground truth):
public XmlMementoSerializer(ClassLoader classLoader){
  this.classLoader=checkNotNull(classLoader,"String_Node_Str");
  xstream.alias("String_Node_Str",MutableBrooklynMemento.class);
  xstream.alias("String_Node_Str",BasicEntityMemento.class);
  xstream.alias("String_Node_Str",BasicLocationMemento.class);
  xstream.alias("String_Node_Str",BasicPolicyMemento.class);
  xstream.alias("String_Node_Str",BasicFeedMemento.class);
  xstream.alias("String_Node_Str",BasicEnricherMemento.class);
  xstream.alias("String_Node_Str",BasicConfigKey.class);
  xstream.alias("String_Node_Str",BasicCatalogItemMemento.class);
  xstream.alias("String_Node_Str",BasicAttributeSensor.class);
  xstream.alias("String_Node_Str",Effector.class);
  xstream.addDefaultImplementation(EffectorAndBody.class,Effector.class);
  xstream.alias("String_Node_Str",BasicParameterType.class);
  xstream.addDefaultImplementation(EffectorBodyTaskFactory.class,EffectorTaskFactory.class);
  xstream.alias("String_Node_Str",Entity.class);
  xstream.alias("String_Node_Str",Location.class);
  xstream.alias("String_Node_Str",Policy.class);
  xstream.alias("String_Node_Str",Enricher.class);
  xstream.registerConverter(new LocationConverter());
  xstream.registerConverter(new PolicyConverter());
  xstream.registerConverter(new EnricherConverter());
  xstream.registerConverter(new EntityConverter());
  xstream.registerConverter(new FeedConverter());
  xstream.registerConverter(new CatalogItemConverter());
  xstream.registerConverter(new ManagementContextConverter());
  xstream.registerConverter(new TaskConverter(xstream.getMapper()));
}