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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 assign(self, pm):
 """Reassign pixmap or xpm string array to wrapper"""

        if isinstance(pm, QPixmap):
            self._pm = pm
        else:  # assume xpm string list to be decoded on-demand
            self._xpmstr = pm
            self._pm = None
        self._icon = None