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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_item(self, sqla_col_type, item, key_specific=None):
 """ Add an item to the registry """

        if key_specific is not None:
            self.setdefault(key_specific, {})[sqla_col_type] = item
        else:
            self[sqla_col_type] = item