def generate(self, chars):
        """Generate audio CAPTCHA data. The return data is a bytearray.

        :param chars: text to be generated.
        """
        if not self._cache:
            self.load()
        body = self.create_wave_body(chars)
        return patch_wave_header(body)
Generate audio CAPTCHA data. The return data is a bytearray.

        :param chars: text to be generated.