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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 raise_if_cant_commit(self):
 """Verify VCS status and raise an error if commit is disallowed :return: """

        cmd = self._command.status()

        (code, stdout, stderr) = self._exec(cmd)

        if code:
            raise errors.VCSError('Can\'t verify VCS status. Process exited with code %d and message: %s' % (
                code, stderr or stdout))

        for line in stdout.splitlines():
            if line.startswith(('??', '!!')):
                continue
            raise errors.VCSStateError("VCS status doesn't allow to commit. Please commit or stash your changes and try again")