title: why undefined error in the following backbone view codes?
body: <pre><code>const _ = require('underscore');
  
  module.exports = (() =&gt; {
    const PANEL_HEADER_HEIGHT = 40;
  
    return Frame.extend({
  
    ...
      _handleSearch: _.debounce(ev =&gt; {
        if ( ev.keyCode !== 9 ) {
          const searchValue = $(ev.target).val();
          this.model.filterData(searchValue);
        }
      }, 1000),
     ...
  })();
  </code></pre>
  
  <blockquote>
    <p>this.model.filterData(searchValue); <strong>converted to</strong>
    <strong>undefined.model</strong>.filterData(searchValue); in console.</p>
  </blockquote>
  
  <p>Any idea?</p>