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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 relabel(self, change):
        "Relabel images by moving from parent dir with old label `class_old` to parent dir with new label `class_new`."
        class_new,class_old,file_path = change.new,change.old,change.owner.file_path
        fp = Path(file_path)
        parent = fp.parents[1]
        self._csv_dict[fp] = class_new