cast<RK, RV> method
Provides a view of this map as having RK keys and RV instances,
if necessary.
If this map is already a Map<RK, RV>, it is returned unchanged.
If this set contains only keys of type RK and values of type RV,
all read operations will work correctly.
If any operation exposes a non-RK key or non-RV value,
the operation will throw instead.
Entries added to the map must be valid for both a Map<K, V> and a
Map<RK, RV>.
Methods which accept Object? as argument,
like containsKey, remove and operator [],
will pass the argument directly to the this map's method
without any checks.
That means that you can do mapWithStringKeys.cast<int,int>().remove("a")
successfully, even if it looks like it shouldn't have any effect.
Implementation
@override
UnmodifiableMapView<RK, RV> cast<RK, RV>() => UnmodifiableMapView<RK, RV>(internalMap.cast<RK, RV>());