text: from django.contrib.auth.models import User
  from django.core.validators import RegexValidator
  from django.db import models
  from django_extensions.db.models import TimeStampedModel
  from s3_file_field.fields import S3FileField
  
  from isic.core.constants import MONGO_ID_REGEX
  from isic.core.models.image import Image
  
  
  class Segmentation(TimeStampedModel):
      class Meta:
          ordering = ['id']
  
      girder_id = models.CharField(
          unique=True,
          max_length=24,
          validators=[RegexValidator(f'^{MONGO_ID_REGEX}$')],
      )
      creator = models.ForeignKey(User, on_delete=models.RESTRICT)
      image = models.ForeignKey(Image, on_delete=models.RESTRICT)
      mask = S3FileField(null=True)
      meta = models.JSONField(default=dict)
  
  
  class SegmentationReview(TimeStampedModel):
      creator = models.ForeignKey(User, on_delete=models.RESTRICT)
      segmentation = models.ForeignKey(Segmentation, on_delete=models.CASCADE, related_name='reviews')
      approved = models.BooleanField()
      skill = models.CharField(max_length=6, choices=[('novice', 'novice'), ('expert', 'expert')])
  