pub fn remove_bin<K>(&mut self, key: K) -> Option<MetadataValue<Binary>>
    where
        K: AsMetadataKey<Binary>,
    {
        key.remove(self)
    }
Like remove, but for Binary keys (for example "trace-proto-bin").

# Examples

```
# use tonic::metadata::*;
let mut map = MetadataMap::new();
map.insert_bin("trace-proto-bin", MetadataValue::from_bytes(b"hello.world"));

let prev = map.remove_bin("trace-proto-bin").unwrap();
assert_eq!("hello.world", prev);

assert!(map.remove_bin("trace-proto-bin").is_none());

// Attempting to remove a key of the wrong type fails by not
// finding anything.
map.append("host", "world".parse().unwrap());
assert!(map.remove_bin("host").is_none());
assert!(map.remove_bin("host".to_string()).is_none());
assert!(map.remove_bin(&("host".to_string())).is_none());

// Attempting to remove an invalid key string fails by not
// finding anything.
assert!(map.remove_bin("host{}-bin").is_none());
assert!(map.remove_bin("host{}-bin".to_string()).is_none());
assert!(map.remove_bin(&("host{}-bin".to_string())).is_none());
```
tonic/src/metadata/map.rs