toMap<K, U> method
Implementation
Map<K, U> toMap<K, U>({ required K Function(T item)? funcKey, required U Function(T item)? funcValue }) {
assert(funcKey != null);
assert(funcValue != null);
Map<K, U> map = { for (var item in this) funcKey!(item) : funcValue!(item) };
return map;
}