title: Leverage browser caching external files
body: <p>I used google pagespeed Insights to test the performance of my nodejs website. For some of external files it is saying to leverage browser caching but I don't know how to do this ?</p>
  
  <p>Leverage browser caching</p>
  
  <p>Setting an expiry date or a maximum age in the HTTP headers for static resources instructs the browser to load previously downloaded resources from local disk rather than over the network.
  Leverage browser caching for the following cacheable resources:</p>
  
  <p><a href="http://maps.googleapis.com/">http://maps.googleapis.com/</a>…kwPPoBErK_--SlHZI28k6jjYLyU&amp;sensor=false (30 minutes)</p>
  
  <p><a href="http://www.google-analytics.com/analytics.js">http://www.google-analytics.com/analytics.js</a> (2 hours)</p>
  
  <p>Anyone please help me on this.</p>