old_contents: '''These are the only serializer fields support by the Alexa skills kit'''
  from rest_framework.serializers import CharField, IntegerField, DateField, TimeField, DurationField, ChoiceField # flake8: noqa
  
  # This maps serializer fields to the amazon intent slot types
  INTENT_SLOT_TYPES = {
      "CharField": "AMAZON.LITERAL",
      "IntegerField": "AMAZON.NUMBER",
      "DateField": "AMAZON.DATE",
      "TimeField": "AMAZON.TIME",
      "DurationField": "AMAZON.DURATION",
  }
  
  # Choicefield does not have a amazon mapping because it represents
  # a custom slot type which has but has to have a defined choice set in the
  # alexa skills kit interaction model
  VALID_SLOT_TYPES = INTENT_SLOT_TYPES.keys() + [
      "ChoiceField"
  ]
  
  
new_contents: '''These are the only serializer fields support by the Alexa skills kit'''
  from rest_framework.serializers import CharField, IntegerField, DateField, TimeField, DurationField, ChoiceField # flake8: noqa
  
  # This maps serializer fields to the amazon intent slot types
  INTENT_SLOT_TYPES = {
      "CharField": "AMAZON.LITERAL",
      "IntegerField": "AMAZON.NUMBER",
      "DateField": "AMAZON.DATE",
      "TimeField": "AMAZON.TIME",
      "DurationField": "AMAZON.DURATION",
      "USCityField": "AMAZON.US_CITY",
      "FirstNameField": "AMAZON.US_FIRST_NAME",
      "USStateField": "AMAZON.US_STATE",
      "FourDigitField": "AMAZON.FOUR_DIGIT_NUMBER",
  }
  
  # Choicefield does not have a amazon mapping because it represents
  # a custom slot type which has but has to have a defined choice set in the
  # alexa skills kit interaction model
  VALID_SLOT_TYPES = INTENT_SLOT_TYPES.keys() + [
      "ChoiceField"
  ]
  
  
  class USCityField(CharField):
  
      def __init__(self, **kwargs):
          super(USCityField, self).__init__(**kwargs)
  
  class FirstNameField(CharField):
  
      def __init__(self, **kwargs):
          super(FirstNameField, self).__init__(**kwargs)
  
  class USStateField(CharField):
  
      def __init__(self, **kwargs):
          super(USStateField, self).__init__(**kwargs)
  
  class FourDigitField(IntegerField):
  
      def __init__(self, **kwargs):
          super(FourDigitField, self).__init__(**kwargs)
  
subject: Add support for new slot types