title: How to Maintain order of insertion
body: <p>I want to add a key, value pair into a hashtable (or any other collection) but have to maintain insertion order. How can I do this?</p>
  
  <p>Like I'll add 1 as key "one" as value, 2 as key and "two" as value.</p>
  
  <p>The output should be:</p>
  
  <pre><code>1:one
  2:two
  </code></pre>