Creating BPMN multi instance with external task

How to create bpmn file with external task with multi instance and verify it 

<?xml version="1.0" encoding="UTF-8"?>

<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"

             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

             xsi:schemaLocation="http://www.omg.org/spec/BPMN/20100524/MODEL BPMN20.xsd"

             id="definitions"

             targetNamespace="http://bpmn.io/schema/bpmn">

  <process id="external_task_multi_instance" isExecutable="true">

  

    <startEvent id="startEvent" />

    

    <serviceTask id="externalTask" name="External Task" camunda:type="external" camunda:topic="sampleTopic">

      <multiInstanceLoopCharacteristics isSequential="true">

        <loopCardinality>5</loopCardinality>

        <inputDataItem>

          <camunda:inputData ref="loopDataInput" />

        </inputDataItem>

      </multiInstanceLoopCharacteristics>

    </serviceTask>

    

    <endEvent id="endEvent" />

    

    <sequenceFlow id="flow1" sourceRef="startEvent" targetRef="externalTask" />

    <sequenceFlow id="flow2" sourceRef="externalTask" targetRef="endEvent" />

    

    <dataObjectReference id="loopDataInput" />

    

  </process>

  

</definitions>