Type Alias DropSink 

pub type DropSink = Arc<dyn Fn(&str, &[u8]) -> Result<String, AxError> + Send + Sync>;

Where a file dropped onto the composer goes: its name and its bytes in, the absolute path the city kept it at out (crates/wire/spec/Server.lean §8-49).

Aliased Type

pub struct DropSink { /* private fields */ }