Stop/Start mule flow via web service

mule-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns="http://www.mulesoft.org/schema/mule/core"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="
http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
">

    <flow name="StartWidgetFlow">
        <inbound-endpoint ref="startWidgetEndpoint"/>
        <logger level="INFO" category="StartWidgetFlow" message="Starting app Widget Services..."/>
        <expression-component>app.registry.WidgetFlow.start();</expression-component>
        <set-payload value='{"status":"started"}'/>
        <http:response-builder status="200" contentType="application/json"/>
        <logger level="INFO" category="StartWidgetFlow" message="app Widget Services Started"/>
    </flow>

    <flow name="StopWidgetFlow">
        <inbound-endpoint ref="stopWidgetEndpoint"/>
        <logger level="INFO" category="StopWidgetFlow" message="Stopping app Widget Services..."/>
        <expression-component>app.registry.WidgetFlow.stop();</expression-component>
        <set-payload value='{"status":"stopped"}'/>
        <http:response-builder status="200" contentType="application/json"/>
        <logger level="INFO" category="StopWidgetFlow" message="app Widget Services Stopped"/>
    </flow>
</mule>