title: Filter nil values from Clojure map?
body: <p>What is the best way to filter <code>nil</code> values from a Clojure map <code>{}</code>?</p>
  
  <pre><code>{ :a :x :b nil :c :z }
  ;;=&gt;  { :a :x, :c :z }
  </code></pre>