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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_version(cls):
 """ Return the version number of the tool. """

        cmd_pieces = [cls.tool, '--version']
        process = Popen(cmd_pieces, stdout=PIPE, stderr=PIPE)
        out, err = process.communicate()
        if err:
            return ''
        else:
            return out.splitlines()[0].strip()