How to use the emmett.ctx.current._close_ function in emmett

def current_ctx(app, path):
    builder = ScopeBuilder(path)
    token = current._init_(FakeRequestContext, app, builder.get_data()[0])
    yield current
    current._close_(token)

def current_ctx(path, app=None):
    builder = ScopeBuilder(path)
    token = current._init_(FakeRequestContext, app, builder.get_data()[0])
    yield current
    current._close_(token)

async def handle_request(self, scope, receive, send):
        ctx_token = current._init_(WSContext, self.app, scope, receive, send)
        try:
            await self.pre_handler(scope, receive, send)
        except asyncio.CancelledError:
            if not scope.get('emt._flow_cancel', False):
                self.app.log.exception('Application exception:')
        except Exception:
            self.app.log.exception('Application exception:')
            # http = HTTP(
            #     500, await self.error_handler(), headers=response.headers)
        current._close_(ctx_token)

async def handle_request(self, scope, receive, send):
        ctx_token = current._init_(RequestContext, self.app, scope)
        try:
            http = await self.pre_handler(scope, receive, send)
        except asyncio.CancelledError:
            if not scope.get('emt._flow_cancel', False):
                self.app.log.exception('Application exception:')
                http = HTTP(
                    500, await self.error_handler(), headers=response.headers)
            else:
                current._close_(ctx_token)
                return
        except Exception:
            self.app.log.exception('Application exception:')
            http = HTTP(
                500, await self.error_handler(), headers=response.headers)
        current._close_(ctx_token)
        # TODO: timeout from app config/response
        await asyncio.wait_for(http.send(scope, send), None)