text: from connexion.apps.flask_app import FlaskJSONEncoder
  import six
  
  from xpctl.xpserver.models.base_model_ import Model
  
  
  class JSONEncoder(FlaskJSONEncoder):
      include_nulls = False
  
      def default(self, o):
          if isinstance(o, Model):
              dikt = {}
              for attr, _ in six.iteritems(o.swagger_types):
                  value = getattr(o, attr)
                  if value is None and not self.include_nulls:
                      continue
                  attr = o.attribute_map[attr]
                  dikt[attr] = value
              return dikt
          return FlaskJSONEncoder.default(self, o)
  