<eventSource name="SampleEventSource" xmlns="http://ws.apache.org/ns/synapse">
     <subscriptionManager class="org.apache.synapse.eventing.managers.DefaultInMemorySubscriptionManager">
          <property name="topicHeaderName" value="Topic"/>
          <property name="topicHeaderNS" value="http://apache.org/aip"/>
     </subscriptionManager>
</eventSource>

