code: def to_ufo_blue_values(self, ufo, master):
      
  
      alignment_zones = master.alignmentZones
      blue_values = []
      other_blues = []
      for zone in sorted(alignment_zones):
          pos = zone.position
          size = zone.size
          val_list = blue_values if pos == 0 or size >= 0 else other_blues
          val_list.extend(sorted((pos, pos + size)))
  
      ufo.info.postscriptBlueValues = blue_values
      ufo.info.postscriptOtherBlues = other_blues
docs: Set postscript blue values from Glyphs alignment zones.