     private let automaticErrorHandling: Bool
 
     #if swift(>=5.7)
+    // FIXME: remove @unchecked when 5.7 is the minimum supported version.
     /// Create a new `NIOWebSocketServerUpgrader`.
     ///
     /// - parameters:

        }
    }
}

#if swift(>=5.6)
@available(*, unavailable)
extension NIOWebSocketServerUpgrader: Sendable {}
#endif


///
/// This upgrader assumes that the `HTTPServerUpgradeHandler` will appropriately mutate the pipeline to
/// remove the HTTP `ChannelHandler`s.
public final class NIOWebSocketServerUpgrader: HTTPServerProtocolUpgrader, @unchecked Sendable {
    // This type *is* Sendable but we can't express that properly until Swift 5.7. In the meantime
    // the conformance is `@unchecked`.

    /// RFC 6455 specs this as the required entry in the Upgrade header.
    public let supportedProtocol: String = "websocket"

