title: Purpose of :: before include module in ruby
body: <p>What is the different between the following two include statements:</p>
  
  <pre><code>include ::Module1:Module2
  </code></pre>
  
  <p>and </p>
  
  <pre><code>include Module1::Module2
  </code></pre>
  
  <p>Both worked in my case. But, I just wonder which one is better (or both are totally fine).</p>