text: from django.db import models
  from django.contrib.postgres.fields import JSONField
  
  from .dataset import Dataset
  
  class Group(models.Model):
      name = models.CharField(max_length=100, blank=False, null=False)
      dataset = models.ForeignKey(Dataset, null=True, on_delete=models.CASCADE)
      subindicators = JSONField(blank=True, default=list)
  
      def __str__(self):
          return f"{self.dataset.name}|{self.name}"
  
      class Meta:
          verbose_name = "SubindicatorsGroup"
          ordering = ("name",)
  