def to_h
      details.reject do |key|
        !KEYS.include?(key)
      end.deep_transform_keys { |key| key.to_s.camelize }
    end
def to_h
      details.reject do |key|
        !KEYS.include?(key)
      end.deep_transform_keys { |key| key.to_s.camelize }
    end
Converts hash keys to Pascal case and rejects invalid keys.

   :sales_order_keys #=> 'SalesOrderKeys'