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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 add_asset(self, ):
 """Add a asset and store it in the self.assets :returns: None :rtype: None :raises: None """

        i = self.asset_treev.currentIndex()
        item = i.internalPointer()
        if item:
            asset = item.internal_data()
            if not isinstance(asset, djadapter.models.Asset):
                return
            if self._shot:
                self._shot.assets.add(asset)
            else:
                self._asset.assets.add(asset)
            self.assets.append(asset)
            item.set_parent(None)