Gets the spec from a spec.
function _getViewSpec(item, view, id, callback) {
        if (!item.view) {
            return;
        }
        var spec = view.getSpec(id);
        if (spec && !spec.trueSizeRequested) {
            callback(spec);
        }
        else {
            Timer.after(_getViewSpec.bind(this, item, view, id, callback), 1);
        }
    }