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/mio/src/sys/wasi
    
    the code of the file until where you have to start completion: //! # Notes
//!
//! The current implementation is somewhat limited. The `Waker` is not
//! implemented, as at the time of writing there is no way to support to wake-up
//! a thread from calling `poll_oneoff`.
//!
//! Furthermore the (re/de)register functio
    
    pub(crate) fn debug_details(f: &mut fmt::Formatter<'_>, event: &Event) -> fmt::Result {
        debug_detail!(
            TypeDetails(wasi::Eventtype),
            PartialEq::eq,
            wasi::EVENTTYPE_CLOCK,
            wasi::EVENTTYPE_FD_READ,
            wasi::EVENTTYPE_FD_WRITE,
        );

        #[allow(clippy::trivially_copy_pass_by_ref)]
        fn check_flag(got: &wasi::Eventrwflags, want: &wasi::Eventrwflags) -> bool {
            (got & want) != 0
        }
        debug_detail!(
            EventrwflagsDetails(wasi::Eventrwflags),
            check_flag,
            wasi::EVENTRWFLAGS_FD_READWRITE_HANGUP,
        );

        struct EventFdReadwriteDetails(wasi::EventFdReadwrite);

        impl fmt::Debug for EventFdReadwriteDetails {
            fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
                f.debug_struct("EventFdReadwrite")
                    .field("nbytes", &self.0.nbytes)
                    .field("flags", &self.0.flags)
                    .finish()
            }
        }

        f.debug_struct("Event")
            .field("userdata", &event.userdata)
            .field("error", &event.error)
            .field("type", &TypeDetails(event.type_))
            .field("fd_readwrite", &EventFdReadwriteDetails(event.fd_readwrite))
            .finish()
    }