class Rack::Protection::AuthenticityToken

def accepts?(env)
  session = session env
  set_token(session)
  safe?(env) ||
    valid_token?(session, env['HTTP_X_CSRF_TOKEN']) ||
    valid_token?(session, Request.new(env).params[options[:authenticity_param]]) ||
    ( options[:allow_if] && options[:allow_if].call(env) )
end