code: function getVendorPrefixedEventName(eventName) {
    if (prefixedEventNames[eventName]) {
      return prefixedEventNames[eventName];
    } else if (!vendorPrefixes[eventName]) {
      return eventName;
    }
  
    var prefixMap = vendorPrefixes[eventName];
  
    for (var styleProp in prefixMap) {
      if (prefixMap.hasOwnProperty(styleProp) && styleProp in style) {
        return prefixedEventNames[eventName] = prefixMap[styleProp];
      }
    }
  
    return '';
  }
docs: Attempts to determine the correct vendor prefixed event name.
  
  @param {string} eventName
  @returns {string}