in packages/svg-mixer/runtime/src/browser-sprite.js [128:138]
add(symbol) {
const sprite = this;
const isNewSymbol = super.add(symbol);
if (this.isMounted && isNewSymbol) {
symbol.mount(sprite.node);
this._emitter.emit(Events.SYMBOL_MOUNT, symbol.node);
}
return isNewSymbol;
}