pub fn sink() -> Sink {
    Sink { _priv: () }
}
Creates an instance of a writer which will successfully consume all data.

All calls to `poll_write` on the returned instance will return `Poll::Ready(Ok(buf.len()))`
and the contents of the buffer will not be inspected.

# Examples

```rust
# futures::executor::block_on(async {
use futures::io::{self, AsyncWriteExt};

let buffer = vec![1, 2, 3, 5, 8];
let mut writer = io::sink();
let num_bytes = writer.write(&buffer).await?;
assert_eq!(num_bytes, 5);
# Ok::<(), Box<dyn std::error::Error>>(()) }).unwrap();
```
futures-util/src/io/sink.rs