test

    function _renderFieldsInto(panel, fields, properties, form) {

        for (var i = 0; i < fields.length; i++) {

            var field = fields[i];

            // let (not var): field-specific click handlers below (icon_browse,

            // media_browse, ...) close over `field` and only run later, on user

            // interaction — with `var` they'd all share one binding left

            // pointing at the LAST field in the array after the loop ends.

            let field = fields[i];

            var group = document.createElement('div');

            group.className = 'prop-group';

            group.setAttribute('data-level', field.level || 'simple');

    // half that was never wired up.

    function _applyConditionalVisibility(panel, fields) {

        for (var i = 0; i < fields.length; i++) {

            var field = fields[i];

            let field = fields[i];

            if (!field.visibleWhen || !field.visibleWhen.key) continue;

            var group = panel.querySelector('[name="' + field.key + '"]');