code: def visit_regex(self, node, regex):
          
          tilde, literal, flags, _ = regex
          flags = flags.text.upper()
          pattern = literal.literal  # Pull the string back out of the Literal
                                     # object.
          return Regex(pattern, ignore_case='I' in flags,
                                locale='L' in flags,
                                multiline='M' in flags,
                                dot_all='S' in flags,
                                unicode='U' in flags,
                                verbose='X' in flags,
                                ascii='A' in flags)
docs: Return a ``Regex`` expression.