code: function(basename, lan)
  	{
  		if (mxClient.languages == null || !this.isLanguageSupported(lan))
  		{
  			var dash = lan.indexOf('-');
  			
  			if (dash > 0)
  			{
  				lan = lan.substring(0, dash);
  			}
  		}
  
  		if (mxResources.loadSpecialBundle && mxResources.isLanguageSupported(lan) && lan != mxClient.defaultLanguage)
  		{
  			return basename + '_' + lan + mxResources.extension;
  		}
  		else
  		{
  			return null;
  		}
  	}
docs: Function: getSpecialBundle
  
  Hook for subclassers to return the URL for the special bundle. This
  implementation returns basename + '_' + lan + <extension> or null if
  <loadSpecialBundle> is false or lan equals <mxClient.defaultLanguage>.
  
  If <mxResources.languages> is not null and <mxClient.language> contains
  a dash, then this method checks if <isLanguageSupported> returns true
  for the full language (including the dash). If that returns false the
  first part of the language (up to the dash) will be tried as an extension.
  
  If <mxResources.language> is null then the first part of the language is
  used to maintain backwards compatibility.
  
  Parameters:
  
  basename - The basename for which the file should be loaded.
  lan - The language for which the file should be loaded.