code: function attach(filters, instance)
  {
    Object.keys(filters).forEach(function(step)
    {
      filters[step].forEach(function(filter)
      {
        instance.use(step, filter);
      });
    });
  }
docs: Attaches list of middleware filters to the provided instance
  
  @param {object} filters - list of filters per step (event)
  @param {function} instance - filter instance to attach to an event (step)