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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 do_du(self, params):
 """ \x1b[1mNAME\x1b[0m du - Total number of bytes under a path \x1b[1mSYNOPSIS\x1b[0m du [path] \x1b[1mOPTIONS\x1b[0m * path: the path (default: cwd) \x1b[1mEXAMPLES\x1b[0m > du / 90 """

        self.show_output(pretty_bytes(self._zk.du(params.path)))