After this function is called, READER must not ever again
be referenced directly. It will be destroyed automatically
when the filtering casereader is destroyed. */
struct casereader *
casereader_create_filter_missing (struct casereader *reader,
After this function is called, READER must not ever again
be referenced directly. It will be destroyed automatically
when the filtering casereader is destroyed. */
struct casereader *
casereader_create_filter_missing (struct casereader *reader,