You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mod.rs
    path of file: ./repos/dozer/dozer-deno/src/runtime
    
    the code of the file until where you have to start completion: //! `JsRuntime` is `!Send + !Sync`, make it difficult to use.
//! Here we impleme
    
    fn propagate_panic(&mut self) -> ! {
        self.handle
            .take()
            .expect("runtime panicked before and cannot be used again")
            .join()
            .unwrap();
        unreachable!("we should have panicked");
    }