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HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
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<?xml version="1.0"?>
<api>
  <query-continue>
    <allfileusages gafcontinue="BPM_Change_Management_Lifecycle.png" />
  </query-continue>
  <query>
    <pages>
      <page ns="6" title="File:BPMN-Claim-End-2-End-Flows.pdf" missing="" />
      <page pageid="3877" ns="6" title="File:BA Retap - Liquids Workflow.png" />
      <page pageid="3876" ns="6" title="File:BA Retap - Solids Workflow.png" />
      <page pageid="3883" ns="6" title="File:BA Retap Description 05-06-17.docx" />
      <page pageid="3878" ns="6" title="File:BA Retap Description 05-06-17.pdf" />
      <page pageid="2399" ns="6" title="File:BPMN Model.png" />
      <page pageid="2418" ns="6" title="File:BPMN Model Introduction.pdf" />
      <page pageid="2419" ns="6" title="File:BPMN and eXtended BPMN Shapes.pdf" />
      <page pageid="2705" ns="6" title="File:BPM Center of Excellence - Figure 1.png" />
      <page pageid="3427" ns="6" title="File:BPM Change Management Lifecycle.pdf" />
    </pages>
  </query>
</api>