title: Why people formally do this.$el.html() in the very first line of backbone view rendering?
body: <p>There's a Backbone.js view render function below:</p>
  
  <pre class="lang-js prettyprint-override"><code>var bookListView = Backbone.View.extend({
    model: BooksCollection,
  
    render: function() {
      this.$el.html(); // lets render this view
  
      var self = this;
  
      for (var i = 0; i &lt; this.model.length; ++i) {
        // lets create a book view to render
        var m_bookView = new bookView({
          model: this.model.at(i)
        });
  
        // lets add this book view to this list view
        this.$el.append(m_bookView.$el);
        m_bookView.render(); // lets render the book           
      }
  
      return this;
    },
  });
  </code></pre>
  
  <p>I just came to know that people usually add <code>this.$el.html();</code> at the begining of the render function for rendering the view.</p>
  
  <p>However, I have no idea why this code is used on the first line. It just works totally same, even though I remove the first line.</p>