new_contents: from datetime import datetime
  
  import pytz
  
  from cornflake import fields, serializers
  
  
  def parse_sda_datetime(value):
      value = datetime.strptime('%Y-%m-%d %H:%M:%S', value)
      value = value.replace(tzinfo=pytz.UTC)
      return value
  
  
  class SDADateTimeField(fields.DateTimeField):
      def parse(self, data):
          try:
              return parse_sda_datetime(data)
          except ValueError:
              return super(SDADateTimeField, self).parse(data)
  
  
  class CodeDescriptionSerializer(serializers.Serializer):
      code = fields.StringField()
      description = fields.StringField()
  
  
  class AddressSerializer(serializers.Serializer):
      from_time = SDADateTimeField(required=False)
      to_time = SDADateTimeField(required=False)
      street = fields.StringField(required=False)
      city = CodeDescriptionSerializer(required=False)
      state = CodeDescriptionSerializer(required=False)
      country = CodeDescriptionSerializer(required=False)
      zip = CodeDescriptionSerializer(required=False)
  
  
  class ContactInfoSerializer(serializers.Serializer):
      home_phone_number = fields.StringField(required=False)
      work_phone_number = fields.StringField(required=False)
      mobile_phone_number = fields.StringField(required=False)
      email_address = fields.StringField(required=False)
  
  
  class NameSerializer(serializers.Serializer):
      given_name = fields.StringField(required=False)
      family_name = fields.StringField(required=False)
  
  
  class PatientSerializer(serializers.Serializer):
      name = NameSerializer(required=False)
      birth_time = SDADateTimeField(required=False)
      death_time = SDADateTimeField(required=False)
      gender = CodeDescriptionSerializer(required=False)
      ethnic_group = CodeDescriptionSerializer(required=False)
      contact_info = ContactInfoSerializer(required=False)
  
  
  class PatientNumberSerializer(serializers.Serializer):
      number = fields.StringField()
      number_type = fields.StringField()
      organization = CodeDescriptionSerializer()
  
  
  class DrugProductSerializer(serializers.Serializer):
      product_name = fields.StringField()
  
  
  class MedicationSerializer(serializers.Serializer):
      external_id = fields.StringField()
      from_time = SDADateTimeField()
      to_time = SDADateTimeField(required=False)
      dose_u_o_m = CodeDescriptionSerializer()
      drug_product = DrugProductSerializer()
      entering_organization = CodeDescriptionSerializer()
  
  
  class LabResultItemSerializer(serializers.Serializer):
      observation_time = SDADateTimeField()
      test_item_code = CodeDescriptionSerializer()
      result_value = fields.FloatField()
  
  
  class ResultSerializer(serializers.Serializer):
      result_items = fields.ListField(child=LabResultItemSerializer())
  
  
  class LabOrderSerializer(serializers.Serializer):
      external_id = fields.StringField()
      from_time = SDADateTimeField(required=False)
      entering_organization = CodeDescriptionSerializer()
  
  
  class ContainerSerializer(serializers.Serializer):
      class PatientSerializer(serializers.Serializer):
          patient_numbers = fields.ListField(child=PatientNumberSerializer())
  
      patient = PatientSerializer()
      lab_orders = fields.ListField(child=fields.Field(), required=False)
      medications = fields.ListField(child=fields.Field(), required=False)
  
subject: Add missing file