<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def save(self, filename, options=None, text=None):
 """Renders the barcode and saves it in `filename`. :parameters: filename : String Filename to save the barcode in (without filename extension). options : Dict The same as in `self.render`. text : str (unicode on Python 2) Text to render under the barcode. :returns: The full filename with extension. :rtype: String """

        if text:
            output = self.render(options, text)
        else:
            output = self.render(options)

        _filename = self.writer.save(filename, output)
        return _filename