code: function decodeHTMLEntity(htmlEntity) {
      var entities = {
          '&quot;': '"',
          '&amp;': '&',
          '&lt;': '<',
          '&gt;': '>',
          '&#39;': '\'',
          '&nbsp;': ' '
      };
  
      return htmlEntity.replace(/&amp;|&lt;|&gt;|&quot;|&#39;|&nbsp;/g, function(m0) {
          return entities[m0] ? entities[m0] : m0;
      });
  }
docs: Transform the given HTML Entity string into plain string
  @param {String} htmlEntity - HTML Entity type string
  @returns {String} Plain string
  @memberof tui.util
  @example
  //-- #1. Get Module --//
  var util = require('tui-code-snippet'); // node, commonjs
  var util = tui.util; // distribution file
  
  //-- #2. Use property --//
  var htmlEntityString = "A &#39;quote&#39; is &lt;b&gt;bold&lt;/b&gt;"
  var result = util.decodeHTMLEntity(htmlEntityString); //"A 'quote' is <b>bold</b>"