lib/utils.js
function(callback){
			if(!this.id){
				return process.nextTick(function(){
					callback(new Error("Invalid session ID"));
				});
			}
			options.client.expire(options.keyspace + this.id, options.maxAge, callback);
		}
function(callback){
			if(!this.id){
				return process.nextTick(function(){
					callback(new Error("Invalid session ID"));
				});
			}
			options.client.expire(options.keyspace + this.id, options.maxAge, callback);
		}
function ( callback ) { if ( ! this . id ) { return process . nextTick ( function ( ) { callback ( new Error ( "Invalid session ID" ) ) ; } ) ; } options . client . expire ( options . keyspace + this . id , options . maxAge , callback ) ; }
update the TTL on a session
update the TTL on a session