def parse(self, reader: TextReader, document: Element) -> str:
    matched = reader.consume(self.pattern)
    if matched:
        return matched.group(0)[:(- 1)]
    else:
        return None
def parse(self, reader: TextReader, document: Element) -> str:
    matched = reader.consume(self.pattern)
    if matched:
        return matched.group(0)[:(- 1)]
    else:
        return None