      members = models.ManyToManyField(ChordsMusician, through='Invitation')
  
  
  class Invitation(models.Model):
      player = models.ForeignKey(ChordsMusician)
      band = models.ForeignKey(ChordsBand)
      instrument = models.CharField(max_length=15)
  
  
  class Swallow(models.Model):
      origin = models.CharField(max_length=255)
 
</s> remove     band = models.ForeignKey(Band)
 </s> add     band = models.ForeignKey(Band, models.CASCADE) </s> remove             band = UnsavedForeignKey(Band)
 </s> add             band = UnsavedForeignKey(Band, models.CASCADE) </s> remove     parent = models.ForeignKey(UUIDPKParent)
 </s> add     parent = models.ForeignKey(UUIDPKParent, models.CASCADE) </s> remove     band = models.ForeignKey(Band)
 </s> add     band = models.ForeignKey(Band, models.CASCADE) </s> remove             band_ct = models.ForeignKey(ContentType)
 </s> add             band_ct = models.ForeignKey(ContentType, models.CASCADE)
    player = models.ForeignKey(ChordsMusician, models.CASCADE)
    band = models.ForeignKey(ChordsBand, models.CASCADE)
      members = models.ManyToManyField(ChordsMusician, through='Invitation')
  
  
  class Invitation(models.Model):
    player = models.ForeignKey(ChordsMusician, models.CASCADE)
    band = models.ForeignKey(ChordsBand, models.CASCADE)
    player = models.ForeignKey(ChordsMusician, models.CASCADE)
    band = models.ForeignKey(ChordsBand, models.CASCADE)
      instrument = models.CharField(max_length=15)
  
  
  class Swallow(models.Model):
      origin = models.CharField(max_length=255)
keep keep keep keep replace replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/admin_changelist/models.py