in packages/svg-mixer/lib/transformations/move-nodes-outside-symbol.js [27:34]
traverse(node.content).forEach(function (n) {
if (!this.isLeaf && n.tag && cfg.tags.indexOf(n.tag) !== -1) {
const parent = this.parent.node;
const cloned = clone(this.node);
symbol.push(cloned);
nodesToRemove.push({ parent, node: n });
}
});