code: def decode_sql(self, sql):
          
          # JSON is defined as using "unicode", we'll go a step further and
          # mandate utf-8 (though for the base64 part, it doesn't really matter!)
          base64_sql_bytes = to_unicode(sql).encode('utf-8')
          # in python3.x you can pass `validate=True` to b64decode to get this
          # behavior.
          if not re.match(b'^[A-Za-z0-9+/]*={0,2}$', base64_sql_bytes):
              self.raise_invalid_base64(sql)
  
          try:
              sql_bytes = base64.b64decode(base64_sql_bytes)
          except ValueError:
              self.raise_invalid_base64(sql)
  
          return sql_bytes.decode('utf-8')
docs: Base64 decode a string. This should only be used for sql in calls.
  
          :param str sql: The base64 encoded form of the original utf-8 string
          :return str: The decoded utf-8 string