Use optimized implementation for positive set filter.
Use optimized implementation for positive set filter.

woodymit/millstone_accidental_source,woodymit/millstone_accidental_source,churchlab/millstone,woodymit/millstone_accidental_source,churchlab/millstone,woodymit/millstone,woodymit/millstone,woodymit/millstone_accidental_source,churchlab/millstone,woodymit/millstone,woodymit/millstone,churchlab/millstone