pub trait LogFlusherProxyInterface: Send + Sync {
    type WaitUntilFlushedResponseFut: Future<Output = Result<(), Error>> + Send;
    // Required method
    fn wait_until_flushed(&self) -> Self::WaitUntilFlushedResponseFut;
}pub trait LogFlusherProxyInterface: Send + Sync {
    type WaitUntilFlushedResponseFut: Future<Output = Result<(), Error>> + Send;
    // Required method
    fn wait_until_flushed(&self) -> Self::WaitUntilFlushedResponseFut;
}