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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 verify(self, string_version=None):
 """ Check that the version information is consistent with the VCS before doing a release. If supplied with a string version, this is also checked against the current version. Should be called from setup.py with the declared package version before releasing to PyPI. """

        if string_version and string_version != str(self):
            raise Exception("Supplied string version does not match current version.")

        if self.dirty:
            raise Exception("Current working directory is dirty.")

        if self.release != self.expected_release:
            raise Exception("Declared release does not match current release tag.")

        if self.commit_count !=0:
            raise Exception("Please update the VCS version tag before release.")

        if self._expected_commit not in [None, "$Format:%h$"]:
            raise Exception("Declared release does not match the VCS version tag")