old_contents: """
  api/serializers.py
  
  Serializers allow complex data to be converted to native Python datatypes that
  can then be easily rendered into JSON, XML or other content types.
  
  http://www.django-rest-framework.org/api-guide/serializers
  """
  # Future Imports
  from __future__ import (absolute_import, division, print_function,
                          unicode_literals)
  
  # App Imports
  from .models import Category, Facility, Schedule, OpenTime, Location
  
  # Other Imports
  from rest_framework import serializers
  
  class CategorySerializer(serializers.ModelSerializer):
      """
      Serializer for the Category model.
      """
      class Meta:
          # Choose the model to be serialized
          model = Category
          # Serialize all of the fields
          fields = '__all__'
  
  class LocationSerializer(serializers.ModelSerializer):
      """
      Serializer for the Location model.
      """
      class Meta:
          # Choose the model to be serialized
          model = Location
          # Serialize all of the fields
          fields = '__all__'
  
  class OpenTimeSerializer(serializers.ModelSerializer):
      """
      Serializer for the OpenTime model.
      """
      class Meta:
          # Choose the model to be serialized
          model = OpenTime
          # Serialize all of the fields
          fields = '__all__'
  
  class ScheduleSerializer(serializers.ModelSerializer):
      """
      Serializer for the Schedule model.
      """
      # Append a serialized OpenTime object
      open_times = OpenTimeSerializer(many=True, read_only=True)
  
      class Meta:
          # Choose the model to be serialized
          model = Schedule
          # List the fields that we are serializing
          fields = ('id', 'open_times', 'modified', 'name', 'valid_start',
                    'valid_end')
  
  class FacilitySerializer(serializers.HyperlinkedModelSerializer):
      """
      Serializer for the Facility model.
      """
      # Append a serialized Category object
      facility_category = CategorySerializer(many=False, read_only=True)
      # Append a serialized Location object
      facility_location = LocationSerializer(many=False, read_only=True)
      # Append a serialized Schedule object to represent main_schedule
      main_schedule = ScheduleSerializer(many=False, read_only=True)
      # Append a serialized Schedule object to represent special_schedules
      special_schedules = ScheduleSerializer(many=True, read_only=True)
  
      class Meta:
          # Choose the model to be serialized
          model = Facility
          # List the fields that we are serializing
          fields = ('id', 'facility_category', 'facility_location',
                    'main_schedule', 'special_schedules', 'modified', 'name')
  
new_contents: """
  api/serializers.py
  
  Serializers allow complex data to be converted to native Python datatypes that
  can then be easily rendered into JSON, XML or other content types.
  
  http://www.django-rest-framework.org/api-guide/serializers
  """
  # Future Imports
  from __future__ import (absolute_import, division, print_function,
                          unicode_literals)
  
  # App Imports
  from .models import Category, Facility, Schedule, OpenTime, Location
  
  # Other Imports
  from rest_framework import serializers
  
  class CategorySerializer(serializers.ModelSerializer):
      """
      Serializer for the Category model.
      """
      class Meta:
          # Choose the model to be serialized
          model = Category
          # Serialize all of the fields
          fields = '__all__'
  
  class LocationSerializer(serializers.ModelSerializer):
      """
      Serializer for the Location model.
      """
      class Meta:
          # Choose the model to be serialized
          model = Location
          # Serialize all of the fields
          fields = '__all__'
  
  class OpenTimeSerializer(serializers.ModelSerializer):
      """
      Serializer for the OpenTime model.
      """
      class Meta:
          # Choose the model to be serialized
          model = OpenTime
          # Serialize all of the fields
          fields = '__all__'
  
  class ScheduleSerializer(serializers.ModelSerializer):
      """
      Serializer for the Schedule model.
      """
      # Append a serialized OpenTime object
      open_times = OpenTimeSerializer(many=True, read_only=True)
  
      class Meta:
          # Choose the model to be serialized
          model = Schedule
          # List the fields that we are serializing
          fields = ('id', 'open_times', 'modified', 'name', 'valid_start',
                    'valid_end')
  
  class FacilitySerializer(serializers.HyperlinkedModelSerializer):
      """
      Serializer for the Facility model.
  
      From the docs:
          The HyperlinkedModelSerializer class is similar to the ModelSerializer
          class except that it uses hyperlinks to represent relationships, rather
          than primary keys.
          http://www.django-rest-framework.org/api-guide/serializers/#hyperlinkedmodelserializer
      """
      # Append a serialized Category object
      facility_category = CategorySerializer(many=False, read_only=True)
      # Append a serialized Location object
      facility_location = LocationSerializer(many=False, read_only=True)
      # Append a serialized Schedule object to represent main_schedule
      main_schedule = ScheduleSerializer(many=False, read_only=True)
      # Append a serialized Schedule object to represent special_schedules
      special_schedules = ScheduleSerializer(many=True, read_only=True)
  
      class Meta:
          # Choose the model to be serialized
          model = Facility
          # List the fields that we are serializing
          fields = ('id', 'facility_category', 'facility_location',
                    'main_schedule', 'special_schedules', 'modified', 'name')
  
subject: Add in a few more words from the docs