title: django rest framework - how to add a static field value for a serializer
body: <p>I need to add a static field to my serializer. It should always return the same value, regardless of the passed object. Currently I implemented it like so:</p>
  
  <pre><code>class QuestionSerializer(serializers.ModelSerializer):
      type = serializers.SerializerMethodField()
  
      @staticmethod
      def get_type(obj):
          return 'question'
  
      class Meta:
          model = Question
          fields = ('type',)
  </code></pre>
  
  <p>But is there a simpler way to do it, without the <code>SerializerMethodField</code>?</p>