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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def from_str(cls, tagstring):
 """Create a tag by parsing the tag of a message :param tagstring: A tag string described in the irc protocol :type tagstring: :class:`str` :returns: A tag :rtype: :class:`Tag` :raises: None """

        m = cls._parse_regexp.match(tagstring)
        return cls(name=m.group('name'), value=m.group('value'), vendor=m.group('vendor'))