How to combine dynamic image spec with static one?

[Igor]

I'm trying to figure out how to Crop() based on model saved dimensions while using accessor name for resizing.

Example:

class AvatarThumbnail(ImageSpec):
    format = 'JPEG'
    options = {'quality': 60}

    @property
    def processors(self):
        model, field_name = get_field_info(self.source)
        return [
           Crop(width=model.thumbnail_width, height=thumbnail.avatar_height),
           ResizeToFill(?????????????),
        ]
register.generator('myapp:profile:avatar_thumbnail', AvatarThumbnail)


class Profile(models.Model):
    avatar = models.ImageField(upload_to='avatars')
    small_thumbnail = ImageSpecField(source='avatar',
                                      id='myapp:profile:avatar_thumbnail')
    large_thumbnail = ImageSpecField(source='avatar',
                                      id='myapp:profile:avatar_thumbnail')
   
    thumbnail_width = models.PositiveIntegerField()
    thumbnail_height = models.PositiveIntegerField()

In this example how would ResizeToFill change dimensions based on `small_thumbnail` vs `large_thumbnail`?

Thanks!

[Igor]

solved this with

class Profile(models.Model):

  @property
  def small_thumbnail(self):
   self.sizes = (50,50)
   return self._spec

  _spec =ImageSpecField(source='avatar',

   id='myapp:profile:avatar_thumbnail')

then inside spec I pick it up from model.sizes