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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 _update_list_store_entry(self, list_store, config_key, config_value):
 """Helper method to update a list store :param Gtk.ListStore list_store: List store to be updated :param str config_key: Config key to search for :param config_value: New config value :returns: Row of list store that has been updated :rtype: int """

        for row_num, row in enumerate(list_store):
            if row[self.KEY_STORAGE_ID] == config_key:
                row[self.VALUE_STORAGE_ID] = str(config_value)
                row[self.TOGGLE_VALUE_STORAGE_ID] = config_value
                return row_num