title: Exclude Filters Using InstantSearch.js?
body: <p>We are using Algolia to index content from a variety of sources and for a dozen different products.  Right now I have one index and product is a configured facet.</p>
  
  <p>I need to find a way to restrict searches to only those products the user owns.</p>
  
  <p>I'm using the InstantSearch library and I've been reading through the documentation and various online forums for information on how to accomplish this.</p>
  
  <p>Here is the code I'm trying to get working.</p>
  
  <pre><code>var client = algoliasearch("myAppId", "myApiKey")
  var index = client.initIndex('myIndex');
  
  var search = instantsearch({
  appId: 'myAppId',
  apiKey: 'myApiKey',
  indexName: 'myIndex',
  urlSync: {},
  attributesToHighlight: 'full'
  });
  
  search.addWidget(
  instantsearch.widgets.refinementList({
  container: '#products',
  attributeName: 'products',
  operator: 'or',
  limit: 100,
  sortBy: ['name:asc'],
  templates: {
  }
  })
  );
  
  search.addWidget({
  init: function (options) {
      options.helper.addFacetRefinement('products', 'Product A');
  }
  });
  
  search.start();
  </code></pre>
  
  <p>But when I execute this I get an error stating "Uncaught Error: products is not defined in the facets attribute of the helper configuration".</p>
  
  <p>What step am I missing? Or am I approaching this in the wrong way?</p>
  
  <p>Any guidance appreciated.</p>
  
  <p>~ Greg</p>