error: use of deprecated constant `out_event_renamed_to_to_swarm::_w`: The `out_event` attribute has been renamed to `to_swarm`.
 --> tests/ui/fail/out_event_deprecation.rs:6:13
  |
6 | #[behaviour(out_event = "FooEvent", prelude = "libp2p_swarm::derive_prelude")]
  |             ^^^^^^^^^
  |
note: the lint level is defined here
 --> tests/ui/fail/out_event_deprecation.rs:1:9
  |
1 | #![deny(warnings)] // Ensure the warnings we produce surface as errors.
  |         ^^^^^^^^
  = note: `#[deny(deprecated)]` implied by `#[deny(warnings)]`