class Google::Auth::DefaultCredentials

def self.read_creds
  env_var = CredentialsLoader::ACCOUNT_TYPE_VAR
  type = ENV[env_var]
  raise "#{env_var} is undefined in env" unless type
  case type
  when "service_account"
    ServiceAccountCredentials
  when "authorized_user"
    UserRefreshCredentials
  when "external_account"
    ExternalAccount::Credentials
  else
    raise "credentials type '#{type}' is not supported"
  end
end