modules/core/test/rules/synapse-send.xml

<synapse xmlns="http://ws.apache.org/ns/synapse">
    <stage name="xpath">
        <xpath expr="//ns:text" xmlns:ns="urn:text-body">
            <classmediator name="sendBackHelper" class="org.apache.synapse.mediators.SendBack"/>
            <send/>
        </xpath>
    </stage>
</synapse>