JSON support in Aggregate mediator

SpaceX_Sample_1.xml

<?xml version="1.0" encoding="UTF-8"?>
<proxy xmlns="http://ws.apache.org/ns/synapse"
       name="AggregateMessageProxy"
       transports="http https"
       startOnLoad="true">
   <description/>
   <target>
      <inSequence>
         <property name="enclosing_element" scope="default">
               <Aggregated_Stations/>
         </property>
         <clone>
            <target>
               <endpoint name="Cape">
                  <address uri="http://www.mocky.io/v2/5befbf782f000067007a0be4" format="get"/>
               </endpoint>
            </target>
            <target>
               <endpoint name="KSC">
                  <address uri="http://www.mocky.io/v2/5befbfd22f00009a007a0be5" format="get"/>
               </endpoint>
            </target>
            <target>
               <endpoint name="Vandenberg">
                  <address uri="http://www.mocky.io/v2/5befbffe2f00006a007a0be6" format="get"/>
               </endpoint>
            </target>
            <target>
               <endpoint name="BocaChica">
                  <address uri="http://www.mocky.io/v2/5befc02b2f00008a007a0be7" format="get"/>
               </endpoint>
            </target>
         </clone>
      </inSequence>
      <outSequence>
         <aggregate>
            <correlateOn expression="json-eval($.station.no_of_launches)"/>
            <completeCondition>
               <messageCount min="3" max="-1"/>
            </completeCondition>
            <onComplete expression="json-eval($.)" enclosingElementProperty="enclosing_element">
               <property name="messageType" value="application/json" scope="axis2"/>
               <log level="custom">
                  <property name="Aggregated_Stations =========================== "
                            expression="json-eval($.)"/>
               </log>
               <respond/>
            </onComplete>
         </aggregate>
      </outSequence>
   </target>
</proxy>