The model containing the original data to filter
The model that will contain the filtered results. The filter func must iterate over orig_model and add all relevant rows to filter_model. This model is guaranteed to be empty when the filter func is invoked
Function used to collect the rows from a model that should be included in a #DeeFilterModel. To add rows to
filter_modeluse the methods dee_filter_model_append_iter(), dee_filter_model_prepend_iter(), dee_filter_model_insert_iter(), and dee_filter_model_insert_iter_before().The iteration over the original model is purposely left to the map func in order to allow optimized iterations if the the caller has a priori knowledge of the sorting and grouping of the data in the original model.