old_contents: from django.db import models
  from django.contrib.auth.models import User
  
  from ..base import SharedSchemaModel, MultiSchemaManager
  
  User.add_to_class('schemata', models.ManyToManyField(
      'boardinghouse.Schema',
      null=True, blank=True,
      related_name='users',
  ))
  
  class AwareModel(models.Model):
      name = models.CharField(max_length=10, unique=True)
      status = models.BooleanField(default=False)
      
      objects = MultiSchemaManager()
      
      class Meta:
          app_label = 'boardinghouse'
  
  class NaiveModel(SharedSchemaModel):
      name = models.CharField(max_length=10, unique=True)
      status = models.BooleanField(default=False)
      
      class Meta:
          app_label = 'boardinghouse'
new_contents: from django.db import models
  from django.contrib.auth.models import User
  
  from ..base import SharedSchemaModel, MultiSchemaManager
  from boardinghouse import settings
  
  User.add_to_class('schemata', models.ManyToManyField(
      settings.SCHEMA_MODEL,
      null=True, blank=True,
      related_name='users',
  ))
  
  class AwareModel(models.Model):
      name = models.CharField(max_length=10, unique=True)
      status = models.BooleanField(default=False)
      
      objects = MultiSchemaManager()
      
      class Meta:
          app_label = 'boardinghouse'
  
  class NaiveModel(SharedSchemaModel):
      name = models.CharField(max_length=10, unique=True)
      status = models.BooleanField(default=False)
      
      class Meta:
          app_label = 'boardinghouse'
subject: Use settings.SCHEMA_MODEL