ExportManager.js
/**
     * After a bulk data request has been started, a client MAY send a DELETE
     * request to the URL provided in the Content-Location header to cancel the
     * request.
     * 
     * If the request has been completed, a server MAY use the request as a
     * signal that a client is done retrieving files and that it is safe for the
     * sever to remove those from storage.
     * 
     * Following the delete request, when subsequent requests are made to the
     * polling location, the server SHALL return a 404 error and an associated
     * FHIR OperationOutcome in JSON format. 
     */
After a bulk data request has been started, a client MAY send a DELETE
request to the URL provided in the Content-Location header to cancel the
request.

If the request has been completed, a server MAY use the request as a
signal that a client is done retrieving files and that it is safe for the
sever to remove those from storage.

Following the delete request, when subsequent requests are made to the
polling location, the server SHALL return a 404 error and an associated
FHIR OperationOutcome in JSON format.
After a bulk data request has been started a client MAY send a DELETE request to the URL provided in the Content - Location header to cancel the request . If the request has been completed a server MAY use the request as a signal that a client is done retrieving files and that it is safe for the sever to remove those from storage . Following the delete request when subsequent requests are made to the polling location the server SHALL return a 404 error and an associated FHIR OperationOutcome in JSON format .
cancel(res)
    {
        this.delete();
        return lib.outcomes.cancelAccepted(res);
    }
cancel ( res ) { this . delete ( ) ; return lib . outcomes . cancelAccepted ( res ) ; }
After a bulk data request has been started, a client MAY send a DELETE
 request to the URL provided in the Content-Location header to cancel the
 request.
After a bulk data request has been started a client MAY send a DELETE request to the URL provided in the Content - Location header to cancel the request .