publish twice about node-eventstore HOT 4 CLOSED

var eventstore = require('eventstore');
var storage = require('eventstore.mongoDb');
var async = require('async');

publisher = {
    publish: function(evt) {
        console.log('publishing: ');
        console.log(evt);
    }
}

var es = eventstore.createStore();

var store = storage.createStorage({
    host: 'localhost',
    port: 27017,
    db: 'es'
});

es.configure(function() {
    es.use(store);
    es.use(publisher);
});

async.series([
    function(cb) {es.start(function(){cb(null);})},
    function(cb) {
        es.getEventStream('1', 0, function(err, stream) {
            stream.addEvent({id: '1', event:'add', payload:{}});
            stream.commit();
            cb(null);
        });
    }
]);