map<K2, V2> method
Returns a new map where all entries of this map are transformed by
the given f function.
Implementation
Map<K2, V2> map<K2, V2>(MapEntry<K2, V2> transform(K key, V value)) {
var result = <K2, V2>{};
for (var key in this.keys) {
var entry = transform(key, this[key]);
result[entry.key] = entry.value;
}
return result;
}