Message element is not generating

Hello guys,

I am working on bpmn-js-properties-panel 0.8.2 version.

I was working on creating message start event and adding messageRef and message name from properties panel.

after creating messageRef it should create element like

<bpmn2:message id="Message_1brk5e4" name="Message_0ad6dle"/>

but it is not creating the element in xml .

here is generated xml

<bpmn2:process id="Process_1" isExecutable="false">
<bpmn2:extensionElements>
<activiti:executionListener class="" event="start"/>
<activiti:properties>
<activiti:property name="messafe" value="ghfg"/>
</activiti:properties>
</bpmn2:extensionElements>
<bpmn2:startEvent id="StartEvent_1">
<bpmn2:messageEventDefinition messageRef="Message_1brk5e4"/>
</bpmn2:startEvent>
</bpmn2:process>
<bpmndi:BPMNDiagram id="BPMNDiagram_1">
<bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="Process_1">
<bpmndi:BPMNShape id="StartEvent_06w9jx9_di" bpmnElement="StartEvent_1">
<dc:Bounds x="173" y="102" width="36" height="36"/>
<bpmndi:BPMNLabel>
<dc:Bounds x="146" y="138" width="90" height="20"/>
</bpmndi:BPMNLabel>
</bpmndi:BPMNShape>
</bpmndi:BPMNPlane>
</bpmndi:BPMNDiagram>
</bpmn2:definitions>

I dont know what I did wrong in my code .I have edited something in library.

Could anyone suggest where bpmn:message element is creates and where I can find my error.

Found the issue. I was trying to create message start event shape programmatically but missed to add bpmn:message definition