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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 copy(self, sleep=_unset, stop=_unset, wait=_unset, retry=_unset, before=_unset, after=_unset, before_sleep=_unset, reraise=_unset):
 """Copy this object with some parameters changed if needed."""

        if before_sleep is _unset:
            before_sleep = self.before_sleep
        return self.__class__(
            sleep=self.sleep if sleep is _unset else sleep,
            stop=self.stop if stop is _unset else stop,
            wait=self.wait if wait is _unset else wait,
            retry=self.retry if retry is _unset else retry,
            before=self.before if before is _unset else before,
            after=self.after if after is _unset else after,
            before_sleep=before_sleep,
            reraise=self.reraise if after is _unset else reraise,
        )