module AWS::S3::ACLObject::ClassMethods

def object_setter(klass, method_name, cast)
  define_method("#{method_name}=") do |value|
    validate_input(method_name, value)
    if value.kind_of?(cast)
      value = klass.new(value)
    end
    instance_variable_set("@#{method_name}", value)
  end
end