class Coordinates(models.Model):
  x_coordinate = models.SmallIntegerField()
  y_coordinate = models.SmallIntegerField()


class DataPoint2(models.Model):
  # nested model
  label = models.CharField(max_length=50)
  coordinate = models.ForeignKey("Coordinates")


class CoordSerializer(serializers.ModelSerializer):
  class Meta:
    model = Coordinates
    fields = ["x_coordinate", "y_coordinate"]


class DataPoint2Serializer(serializers.ModelSerializer):
  class Meta:
    model = DataPoint2
    fields = ["label", "coordinate"]