public class Pipeline
{
    private IPipeObject _pipeStart, _pipeEnd;

    public Pipeline Append(IPipeObject pipe)
    {
        if (_pipeStart == null)
            _pipeStart = pipe;

        if (_pipeEnd != null)
            _pipeEnd.NextPipe = pipe;

        _pipeEnd = pipe;
        return this;
    }
    public void Start(object state = null)
    {
        _pipeStart.Invoke(state);
    }
}