text: H5.getFunctionName = (function () {
      'use strict';
  
      function getFunctionName(fn) {
          var fnString = fn.toString();
          var startIndex = 'function '.length;
          var endIndex = fnString.indexOf('(');
  
          return fnString.slice(startIndex, endIndex);
      }
  
      return getFunctionName;
  })();
  