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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 unwatch(self_,watcher):
 """ Unwatch watchers set either with watch or watch_values. """

        try:
            self_._watch('remove',watcher)
        except:
            self_.warning('No such watcher {watcher} to remove.'.format(watcher=watcher))