operator + method
Creates a new NotifiableMap that contains the entries of this map and the elements of other in that order.
Implementation
NotifiableMap<K?, V?> operator +(NotifiableMap<K?, V?> other) {
NotifiableMap<K?, V?> newSet = NotifiableMap<K?, V?>.of(_values);
newSet.addAll(other);
return newSet;
}