text: from collections import OrderedDict
  from rest_framework.fields import SkipField
  
  
  class NullableFieldsMixin:
      def to_representation(self, instance):
          # Remove null fields from serialized object
          ret = OrderedDict()
          fields = [field for field in self.fields.values() if not field.write_only]
  
          for field in fields:
              try:
                  attribute = field.get_attribute(instance)
              except SkipField:
                  continue
  
              if attribute is not None:
                  representation = field.to_representation(attribute)
                  if representation is None:
                      # Do not serialize empty objects
                      continue
                  if isinstance(representation, list) and not representation:
                      # Do not serialize empty lists
                      continue
                  ret[field.field_name] = representation
  
          return ret
  