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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 tags_newer(self, versions_file, majors):
 """ Checks this git repo tags for newer versions. @param versions_file: a common.VersionsFile instance to check against. @param majors: a list of major branches to check. E.g. ['6', '7'] @raise RuntimeError: no newer tags were found. @raise MissingMajorException: A new version from a newer major branch is exists, but hasn't been downloaded due to it not being in majors. """

        highest = versions_file.highest_version_major(majors)
        all = self.tags_get()

        newer = _newer_tags_get(highest, all)

        if len(newer) == 0:
            raise RuntimeError("No new tags found.")

        return newer