How to use the xandikos.webdav.create_href function in xandikos

def get_value(self, base_href, resource, el, environ):
        for href in resource.get_group_membership():
            el.append(webdav.create_href(href, base_href=href))

def get_value(self, base_href, resource, el, environ):
        for href in resource.get_calendar_user_address_set():
            el.append(webdav.create_href(href, base_href))

async def get_value(self, base_href, resource, el, environ):
        for href in resource.get_calendar_proxy_write_for():
            el.append(webdav.create_href(href, base_href))

def get_value(self, base_href, resource, el, environ):
        owner_href = resource.get_owner()
        if owner_href is not None:
            el.append(webdav.create_href(owner_href, base_href=base_href))

async def get_value(self, href, resource, el, environ):
        el.append(webdav.create_href(
            resource.get_principal_address(), href))

def get_value(self, href, resource, el, environ):
        el.append(webdav.create_href(resource.get_schedule_inbox_url(), href))

def get_value(self, base_href, resource, el, environ):
        for timezone_service_href in self._timezone_services:
            el.append(webdav.create_href(timezone_service_href, base_href))

async def get_value(self, base_href, resource, el, environ):
        el.append(webdav.create_href(resource.get_source_url(), base_href))