async waterfall & map

var async = require('async.js');
var data = {}
data.time = 12345678;
data.tags = [1,2,3];
function post (data) {
    var results = {};
    results.start = new Date().getTime();
    var updateSession = function(callback) {
        console.log('updateSession')
        results.saved = true;
        console.dir(results);
        callback(null,results);
    }
    var findTag = function(callback){
        console.log('findTag');
        console.dir(item);
        callback(null,(item*10)+'asd');
    }
    var findTags = function(callback) {
        console.log('findTags');
        console.dir(results);
        async.mapSeries(data.tags,findTag,function(e,r){
            results.tags = r;
            console.log('f tags last:'+e,' :'+r);
            callback(null);
        }); 
    }
    var findSessionID = function(callback){
        console.log('findSessionID');
        results.sessionID = '12qdqwd12312eadfadf';
        console.dir(results);
        callback(null);
    }
    var isIndiceName = function(callback){
        console.log('isIndiceName');
        results.isIndiceName = new Date(data.time*1000);
        console.dir(results);
        callback(null);
    }
    async.waterfall([isIndiceName,findSessionID,findTags,updateSession],function(e,r){
        console.log('final');
        console.dir(e);
        console.dir(r);
        results.end = new Date().getTime();
        console.dir(results.end - results.start);
    })

}
post(data);