title: When should I use composite design pattern?
body: <p>I don't understand <strong>when I should use composite design pattern</strong>.
  <em>What kinds of benefits will I get from this design pattern?</em>
  I visited <a href="http://www.dofactory.com" rel="noreferrer">this website</a> but it only tells me about the structure of the design pattern and not the scenarios in which it is used.
  I hope that it will be beneficial to the programmers like me who are starting to learn design pattern.</p>