Return the serializer class depending on request method.
        Attribute of proper serializer should be defined.

def get_serializer_class(self, action=None):
        """
        Return the serializer class depending on request method.
        Attribute of proper serializer should be defined.
        """
        if action is not None:
            return getattr(self, '%s_serializer_class' % action)
        else:
            return super(GenericViewSet, self).get_serializer_class()