title: Merge arrays in Ruby/Rails
body: <p>How can I merge two arrays? Something like this:</p>
  
  <pre><code>@movie = Movie.first()
  @options = Movie.order("RANDOM()").first(3).merge(@movie)
  </code></pre>
  
  <p>But it doesn't work.</p>
  
  <p>In <code>@options</code> I need an array with four elements includes <code>@movie</code>.</p>