title: Extjs4, What is the lazyRender?
body: <p>What is the lazyRender in Extjs?</p>
  
  <p>I couldn't find about that in Extjs document, also I couldn't find any web pages that describe about lazyRender.</p>
  
  <p>May I ask a good example please?</p>
  
  <p>Thanks!</p>