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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 removeItem(self, regItem):
 """ Removes a ClassRegItem object to the registry. Will raise a KeyError if the regItem is not registered. """

        check_class(regItem, ClassRegItem)
        logger.info("Removing {!r} containing {}".format(regItem.identifier, regItem.fullClassName))

        del self._index[regItem.identifier]
        idx = self._items.index(regItem)
        del self._items[idx]