class ActiveModel::Serializer

def self.link(name, *args, &block)


link(:callback, if: :internal?), { "http://example.com/callback" }
@example
link :resource, "http://example.com/resource"
@example
link(:self) { "http://example.com/resource/#{object.id}" }
@example
link(:self) { resource_url(object) }
@example
Define a link on a serializer. 
def self.link(name, *args, &block)
  options = args.extract_options!
  # For compatibility with the use case of passing link directly as string argument
  # without block, we are creating a wrapping block
  _links[name] = Link.new(name, options, block || ->(_serializer) { args.first })
end