def source(self, format='xml', accessible=False):
        """
        Args:
            format (str): only 'xml' and 'json' source types are supported
            accessible (bool): when set to true, format is always 'json'
        """
        if accessible:
            return self.http.get('/wda/accessibleSource').value
        return self.http.get('source?format='+format).value