clear method
Removes all entries from the map.
After this, the map is empty.
final planets = <int, String>{1: 'Mercury', 2: 'Venus', 3: 'Earth'};
planets.clear(); // {}
Implementation
@override
void clear() {
if (null is V) {
updateAll((key, value) => null as V);
} else {
keys.forEach(remove);
}
// if Key contains default value
// else if (this case IndexMap<Field, V> map when map.keys.every((key) => key.defaultValue != null)) {
// map.updateAll((key, value) => key.defaultValue as V);
// }
// throw UnsupportedError('IndexMap default clear operation not defined');
}