old_contents: from rest_framework import serializers
  from core.models import Sensor, Station, Reading
  
  class SensorSerializer(serializers.ModelSerializer):
  	class Meta:
  		model = Sensor
  		fields = ("id", "created", "updated", "name", "data_id", "decimals")
  
  class StationSerializer(serializers.ModelSerializer):
  	class Meta:
  		model = Station
  		fields = ("id", "created", "updated", "name", "goes_id", "sensors")
  
  class ReadingSerializer(serializers.ModelSerializer):
  	class Meta:
  		model = Reading
  		fields = ("id", "created", "updated", "read_time", "value", "sensor", "station")
  
new_contents: from rest_framework import serializers
  from django.contrib.auth.models import User
  from core.models import Sensor, Station, Reading, Message
  
  class SensorSerializer(serializers.ModelSerializer):
      class Meta:
          model = Sensor
          fields = ("id", "created", "updated", "name", "data_id", "decimals")
  
  class StationSerializer(serializers.ModelSerializer):
      class Meta:
          model = Station
          fields = ("id", "created", "updated", "name", "goes_id", "sensors")
  
  class ReadingSerializer(serializers.ModelSerializer):
      class Meta:
          model = Reading
          fields = ("id", "created", "updated", "read_time", "value", "sensor", "station")
  
  class MessageSerializer(serializers.ModelSerializer):
      values = serializers.ListField(child=serializers.IntegerField())
  
      class Meta:
          model = Message
          fields = ("id", "created", "updated", "goes_id", "goes_channel", "goes_spacecraft",
              "arrival_time", "failure_code", "signal_strength", "frequency_offset", "modulation_index",
              "data_quality", "data_source", "recorded_message_length", "values", "message_text", "station")
  
  class UserSerializer(serializers.ModelSerializer):
      class Meta:
          model = User
          fields = ("id", "username")
  
subject: Add message and user serializers.