copyFrom method
Convenient to get new key value from key value collection.
map
The collection of new keys to be obtained.
Implementation
Map<K, V> copyFrom(Map<K, V> map) {
if (isEmpty) {
return map;
}
if (map.isNotEmpty) {
final Iterable<K> keys = map.keys;
for (final K item in keys) {
final V? itemValue = map[item];
putIfAbsent(item, () => itemValue!);
}
}
return this;
}