def _prepare_multipart_mixed_request(request: HTTPRequestType) -> None:
        """Will execute the multipart policies.

        Does nothing if "set_multipart_mixed" was never called.

        :param request: The request object.
        :type request: ~azure.core.rest.HttpRequest
        """
        multipart_mixed_info = request.multipart_mixed_info  # type: ignore
        if not multipart_mixed_info:
            return

        requests: List[HTTPRequestType] = multipart_mixed_info[0]
        policies: List[SansIOHTTPPolicy] = multipart_mixed_info[1]
        pipeline_options: Dict[str, Any] = multipart_mixed_info[3]

        # Apply on_requests concurrently to all requests
        import concurrent.futures

        def prepare_requests(req):
            if req.multipart_mixed_info:
                # Recursively update changeset "sub requests"
                Pipeline._prepare_multipart_mixed_request(req)
            context = PipelineContext(None, **pipeline_options)
            pipeline_request = PipelineRequest(req, context)
            for policy in policies:
                _await_result(policy.on_request, pipeline_request)

        with concurrent.futures.ThreadPoolExecutor() as executor:
            # List comprehension to raise exceptions if happened
            [  # pylint: disable=expression-not-assigned, unnecessary-comprehension
                _ for _ in executor.map(prepare_requests, requests)
            ]
Will execute the multipart policies.

        Does nothing if "set_multipart_mixed" was never called.

        :param request: The request object.
        :type request: ~azure.core.rest.HttpRequest
        
Solutions/CyberArkAudit/Data Connectors/.python_packages/lib/site-packages/azure/core/pipeline/_base.py