GdaDataModelRow Base implementation for other objects to implement the #GdaDataModel interface based on the usage of This object is not intended to be instanciated directly, but to be inherited. @parent_class: @get_n_rows: @get_n_columns: @get_row: @get_value_at: @is_updatable: @append_values: @append_row: @update_row: @remove_row: