def by_site_id1(self,site_id1: str) -> SiteItemRequestBuilder:
        """
        Provides operations to manage the sites property of the microsoft.graph.site entity.
        param site_id1: The unique identifier of site
        Returns: SiteItemRequestBuilder
        """
        if site_id1 is None:
            raise TypeError("site_id1 cannot be null.")
        from .item.site_item_request_builder import SiteItemRequestBuilder

        url_tpl_params = get_path_parameters(self.path_parameters)
        url_tpl_params["site%2Did1"] = site_id1
        return SiteItemRequestBuilder(self.request_adapter, url_tpl_params)

        Provides operations to manage the sites property of the microsoft.graph.site entity.
        param site_id1: The unique identifier of site
        Returns: SiteItemRequestBuilder
        
msgraph/generated/sites/item/sites/sites_request_builder.py