module Google::Auth::ExternalAccount::ExternalAccountUtils

def service_account_email
  return nil if @service_account_impersonation_url.nil?
  start_idx = @service_account_impersonation_url.rindex "/"
  end_idx = @service_account_impersonation_url.index ":generateAccessToken"
  if start_idx != -1 && end_idx != -1 && start_idx < end_idx
    start_idx += 1
    return @service_account_impersonation_url[start_idx..end_idx]
  end
  nil
end