class Doorkeeper::OAuth::Token

def self.authenticate(request, *methods)
  if token = from_request(request, *methods)
    AccessToken.by_token(token)
  end
end

def self.from_request(request, *methods)
  methods.inject(nil) do |credentials, method|
    method = self.method(method) if method.is_a?(Symbol)
    credentials = method.call(request)
    break credentials unless credentials.blank?
  end
end