class Google::Auth::Credentials

def self.from_application_default options
  scope = options[:scope] || self.scope
  auth_opts = {
    token_credential_uri:   options[:token_credential_uri] || token_credential_uri,
    audience:               options[:audience] || audience,
    target_audience:        options[:target_audience] || target_audience,
    enable_self_signed_jwt: options[:enable_self_signed_jwt] && options[:scope].nil?
  }
  client = Google::Auth.get_application_default scope, auth_opts
  new client, options
end