title: Splat in argument position
body: <p>Why does this code</p>
  
  <pre><code>Hash[*[[:first_name, 'Shane'], [:last_name, 'Harvie']].flatten] 
  </code></pre>
  
  <p>return this</p>
  
  <pre><code>{:first_name=&gt;"Shane", :last_name=&gt;"Harvie"}
  </code></pre>
  
  <p>I know about <code>Array#flatten</code>. But what does the <code>*</code> mean? How can I look for information about it?</p>