def nullable_attributes(*attrs)
      @nullable_attributes ||= []
      if attrs.any?
        @nullable_attributes.map!(&:to_sym).concat(attrs).uniq! if attrs.any?
      end
      @nullable_attributes
    end
def nullable_attributes(*attrs)
      @nullable_attributes ||= []
      if attrs.any?
        @nullable_attributes.map!(&:to_sym).concat(attrs).uniq! if attrs.any?
      end
      @nullable_attributes
    end
Nullable attributes are sent as null in the request