instance method get_session

# File activerecord/lib/active_record/session_store.rb, line 304
      def get_session(env, sid)
        Base.silence do
          unless sid and session = @@session_class.find_by_session_id(sid)
            # If the sid was nil or if there is no pre-existing session under the sid,
            # force the generation of a new sid and associate a new session associated with the new sid
            sid = generate_sid
            session = @@session_class.new(:session_id => sid, :data => {})
          end
          env[SESSION_RECORD_KEY] = session
          [sid, session.data]
        end
      end