title: How to reference a value for a key in a hash
body: <p>I want to be able to reference to a key in a <code>Hash</code> so that if the value for that key changes, so does anything referencing to it like so</p>
  
  <pre><code>hash = {}
  
  hash[1] = "foo"
  hash[2] = hash[1]
  
  hash[1] = "bar"
  
  puts hash[2] # I want this to be "bar"
  </code></pre>
  
  <p>Is this possible? Thanks!</p>