         return promise.futureResult
     }
 
-    public func add0(name: String?, handler: ChannelHandler, first: Bool, promise: EventLoopPromise<Void>) {
+    /// Add the handler to the `ChannelPipeline`. This operation must only be called when within the `EventLoop` thread.
+    private func add0(name: String?, handler: ChannelHandler, first: Bool, promise: EventLoopPromise<Void>) {
         assert(eventLoop.inEventLoop)
 
         if destroyed {

    }
}

private final class TailChannelHandler : _ChannelInboundHandler {
    
    static let sharedInstance = TailChannelHandler()

    }
}

/// Special `ChannelHandler` that forwards all events to the `Channel.Unsafe` implementation.
private final class HeadChannelHandler : _ChannelOutboundHandler {

    static let sharedInstance = HeadChannelHandler()
