def download(<EOL>self, resource_group_name, virtual_wan_name, vpn_sites=None, output_blob_sas_url=None, custom_headers=None, raw=False, polling=True, **operation_config):
raw_result = self._download_initial(<EOL>resource_group_name=resource_group_name,<EOL>virtual_wan_name=virtual_wan_name,<EOL>vpn_sites=vpn_sites,<EOL>output_blob_sas_url=output_blob_sas_url,<EOL>custom_headers=custom_headers,<EOL>raw=True,<EOL>**operation_config<EOL>)<EOL>def get_long_running_output(response):<EOL><INDENT>if raw:<EOL><INDENT>client_raw_response = ClientRawResponse(None, response)<EOL>return client_raw_response<EOL><DEDENT><DEDENT>lro_delay = operation_config.get(<EOL>'<STR_LIT>',<EOL>self.config.long_running_operation_timeout)<EOL>if polling is True: polling_method = ARMPolling(lro_delay, **operation_config)<EOL>elif polling is False: polling_method = NoPolling()<EOL>else: polling_method = polling<EOL>return LROPoller(self._client, raw_result, get_long_running_output, polling_method)<EOL>
Gives the sas-url to download the configurations for vpn-sites in a
        resource group.

        :param resource_group_name: The resource group name.
        :type resource_group_name: str
        :param virtual_wan_name: The name of the VirtualWAN for which
         configuration of all vpn-sites is needed.
        :type virtual_wan_name: str
        :param vpn_sites: List of resource-ids of the vpn-sites for which
         config is to be downloaded.
        :type vpn_sites: list[str]
        :param output_blob_sas_url: The sas-url to download the configurations
         for vpn-sites
        :type output_blob_sas_url: str
        :param dict custom_headers: headers that will be added to the request
        :param bool raw: The poller return type is ClientRawResponse, the
         direct response alongside the deserialized response
        :param polling: True for ARMPolling, False for no polling, or a
         polling object for personal polling strategy
        :return: An instance of LROPoller that returns None or
         ClientRawResponse<None> if raw==True
        :rtype: ~msrestazure.azure_operation.AzureOperationPoller[None] or
         ~msrestazure.azure_operation.AzureOperationPoller[~msrest.pipeline.ClientRawResponse[None]]
        :raises:
         :class:`ErrorException<azure.mgmt.network.v2018_08_01.models.ErrorException>`