class Devise::FailureApp

def http_auth_body
  return i18n_message unless request_format
  method = "to_#{request_format}"
  if method == "to_xml"
    { error: i18n_message }.to_xml(root: "errors")
  elsif {}.respond_to?(method)
    { error: i18n_message }.send(method)
  else
    i18n_message
  end
end