title: Search array of array of strings with NSPredicate
body: <p>I have a NSSearchController that searches an array of arrays. An example of this master array is</p>
  
  <pre><code>[["key1',"value1"],["key2","value2"]]
  </code></pre>
  
  <p>My search function is as follows:</p>
  
  <pre><code>func updateSearchResultsForSearchController(searchController: UISearchController) {
      for (key, val) in zip(self.keys, self.values) {
          pairs.append([key,val])
      }
  
      filteredKeys.removeAll(keepCapacity: false)
      filteredValues.removeAll(keepCapacity: false)
  
      let searchPredicate = NSPredicate(format: "SELF CONTAINS[c] %@", searchController.searchBar.text)
      let searcher = (self.pairs as NSArray).filteredArrayUsingPredicate(searchPredicate)
      println(searcher)
  
      for matched in searcher {
          var appendedKey = matched[0] as! String
          var appendedValue = matched[1] as! String
          filteredKeys.append(appendedKey)
          filteredValues.append(appendedValue)
      }
  
      pairs.removeAll(keepCapacity: false)
  
      self.tableView.reloadData()
  }
  </code></pre>
  
  <p>The problem is with my NSPredicate string, as I am searching an array of arrays, the SELF CONTAINS requires an exact string match to be in the array instead of it just containing it. I really want the subarrays of the master array to contain the string being searched. </p>
  
  <p>I tried "name CONTAINS[c] %@" and "SELF BEGINSWITH[c] %@" Both fail. Does anyone know what predicate string to use to search an array of arrays?</p>