class Rack::MethodOverride

def call(env)
  if allowed_methods.include?(env[REQUEST_METHOD])
    method = method_override(env)
    if HTTP_METHODS.include?(method)
      env[RACK_METHODOVERRIDE_ORIGINAL_METHOD] = env[REQUEST_METHOD]
      env[REQUEST_METHOD] = method
    end
  end
  @app.call(env)
end