# Starts customization
            response_awaited = False
            async with AsyncExitStack() as request_stack:
                scope["fastapi_inner_astack"] = request_stack
                async with AsyncExitStack() as function_stack:
                    scope["fastapi_function_astack"] = function_stack
                    response = await f(request)

                # new contextvars context copy by using a new AnyIO task group.
                # This AsyncExitStack preserves the context for contextvars, not
                # strictly necessary for closing files but it was one of the original
                # intentions.
                # If the AsyncExitStack lived outside of the custom middlewares and
                # contextvars were set, for example in a dependency with 'yield'