title: StackExchange.Redis - How to add items to a Redis Set
body: <p>I'm trying to achieve the following scenarios:</p>
  
  <ol>
  <li>Add 5 items of type <code>T</code> to a new Redis SET</li>
  <li>Add 1 item of type <code>T</code> to an <em>existing</em> Redis SET</li>
  </ol>
  
  <p>(i know SETADD doesn't care if the set is existing, but just listing my scenarios for reference)</p>
  
  <p>I can see there is <code>SetAddAsync(RedisKey, RedisValue value)</code> and <code>SetAddAsync(RedisKey, RedisValue[] values)</code>, but i'm not sure how to work with it (and which overload to use?)</p>
  
  <p>When i've used <code>StringSet</code>, i simply serialize <code>T</code> to a <code>byte[]</code>, then use that as the <code>RedisValue</code> param.</p>
  
  <p>But not sure how to do it for sets.</p>
  
  <p>This is what i have:</p>
  
  <pre><code>var items = values.Select(serializer.Serialize).ToArray();
  await cache.SetAddAsync(key, items);
  </code></pre>
  
  <p>where <code>serializer</code> is a class which converts <code>T</code> to a <code>byte[]</code></p>