class Necklace(models.Model):
    
    ### FIELDS ###
    
    ...

    beads = models.ManyToManyField(Bead, through="BeadSet", blank=True)
    
    ...
    
    ### CACHING METHODS ###
    
    def get_beadsets(self): # cache beadsets query to _beadsets
        try:
            _check = self._beadsets
        except:
            self._beadsets = BeadSet.objects.filter(necklace=self).select_related()
        return self._beadsets
    
    def get_beads(self): # cache beads query to _beads
        try:
            _check = self._beads
        except:
            self._beads = self.beads.all().select_related()
        return self._beads
    
    ...