class Faraday::Adapter::ActionDispatch

def call(env) 

def call(env)
  super
  @session.__send__(env[:method], env[:url].request_uri, env[:body], env[:request_headers])
  resp = @session.response
  save_response(env, resp.status, resp.body, resp.headers)
  @app.call env
end

def initialize(app, session)

Returns nothing.

session - An ActionDispatch::Integration::Session instance.
app - The current Faraday request.

a Rails 3 app using integration tests.
initiating an HTTP request with a web server, this adapter calls
Initializes a new middleware instance for each request. Instead of 
def initialize(app, session)
  super(app)
  @session = session
  @session.reset!
end