old_contents: # Copyright (C) 2011-2012 Yaco Sistemas (http://www.yaco.es)
  # Copyright (C) 2010 Lorenzo Gil Sanchez <lorenzo.gil.sanchez@gmail.com>
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #            http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  import django
  from django.db import models
  from django.contrib.auth.models import User
  from django.conf import settings
  
  if django.VERSION < (1, 7):
      class TestProfile(models.Model):
          user = models.OneToOneField('auth.User')
          age = models.CharField(max_length=100, blank=True)
  
  else:
      from django.contrib.auth.models import AbstractUser
      class TestUser(AbstractUser):
          age = models.CharField(max_length=100, blank=True)
  
new_contents: # Copyright (C) 2011-2012 Yaco Sistemas (http://www.yaco.es)
  # Copyright (C) 2010 Lorenzo Gil Sanchez <lorenzo.gil.sanchez@gmail.com>
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #            http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  import django
  from django.db import models
  from django.contrib.auth.models import User
  from django.conf import settings
  
  if django.VERSION < (1, 7):
      class TestProfile(models.Model):
          user = models.OneToOneField('auth.User')
          age = models.CharField(max_length=100, blank=True)
  
          def process_first_name(self, first_name):
              self.first_name = first_name[0]
  else:
      from django.contrib.auth.models import AbstractUser
      class TestUser(AbstractUser):
          age = models.CharField(max_length=100, blank=True)
  
          def process_first_name(self, first_name):
              self.first_name = first_name[0]
  
subject: Update models.py