appendChildIfNotFound(node, name) {
        let child = this.findChild(node, name);
        if (!child) {
            child = { name, attributes: {}, children: [] };
            this.appendChild(node, child);
        }

        return child;
    }
Append a child if one with the given name is not found.
@param {{}} node - The parent node.
@param {string} name - The child node name.
@returns {{}} The child.