populateData is wrong !

[weiyinfu]

This is the demo of treema http://codecombat.github.io/treema/
There is a head js in this html : http://codecombat.github.io/treema/js/treema.js
This function is wrong:

    TreemaNode.prototype.populateData = function () {
        return this.data = this.data || this.schema["default"] || this.getDefaultValue();
    };

when this.data=0,its populated data will be null , but actually it should be a number 0.
It cost me all the morning.
I hope you can update that demo !