docs: def convert_out(self, obj):
          """Write EMIRUUID header on reduction"""
          newobj = super(ProcessedImageProduct, self).convert_out(obj)
          if newobj:
              hdulist = newobj.open()
              hdr = hdulist[0].header
              if 'EMIRUUID' not in hdr:
                  hdr['EMIRUUID'] = str(uuid.uuid1())
          return newobj