in packages/svg-mixer/lib/sprite-symbols-map.js [15:22]
constructor(symbols = []) {
super(symbols.map(s => {
if (!s.issuers) {
s.issuers = symbols.filter(sb => sb.id === s.id).map(sb => sb.module && sb.module.issuer);
}
return [s.id, s];
}));
}