class ActionDispatch::Request::Session

def self.create(store, req, default_options)

Creates a session hash, merging the properties of the previous session if any. 
def self.create(store, req, default_options)
  session_was = find req
  session     = Request::Session.new(store, req)
  session.merge! session_was if session_was
  set(req, session)
  Options.set(req, Request::Session::Options.new(store, default_options))
  session
end