set_session

# File actionpack/lib/action_controller/session/mem_cache_store.rb, line 38
          def set_session(env, sid, session_data)
            options = env['rack.session.options']
            expiry  = options[:expire_after] || 0
            @pool.set(sid, session_data, expiry)
            return true
          rescue MemCache::MemCacheError, Errno::ECONNREFUSED
            return false
          end