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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 get_tagged_version(self):
 		""" 		Get the version of the local working set as a StrictVersion or 		None if no viable tag exists. If the local working set is itself 		the tagged commit and the tip and there are no local 		modifications, use the tag on the parent changeset. 		"""

		tags = list(self.get_tags())
		if 'tip' in tags and not self.is_modified():
			tags = self.get_parent_tags('tip')
		versions = self.__versions_from_tags(tags)
		return self.__best_version(versions)