class ActiveModel::Serializer::Config

def method_missing(name, *args)
  name = name.to_s
  return @data[name] if @data.include?(name)
  match = name.match(/\A(.*?)([?=]?)\Z/)
  case match[2]
  when "="
    @data[match[1]] = args.first
  when "?"
    !!@data[match[1]]
  end
end