GetParameterRequest after inform

how ACS sends GetParameterNames request after sending Informing response while it receives Inform request ?

My query is how ACS triggers GetParameterNames as soon as it sends Inform response?

Please point me the code in lib/cwmp.ts .
In lib/cwmpt.ts
processRequest → handles the inform request sent by Device.

  1. await inform(sessionContext, rpc); → soap.response and set the context]
  2. wrireResponse to send the inform response.
  3. Setting below varirables.
    sessionContext.state = 1;
    sessionContext.authState = 2;

Please guide me how does ACS generates GetParamterName (ACS request) with same session even after sending inform response. for the below call flow.

-------Inform Request----------->

     <-------Inform Response------------


     ------GetParameterNames response----------->

    <-------GetParameterValues ------------

    ------GetParametervalue response----------->

     ------SetParametervalue response----------->