cast< RK, RV> method
override
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>.
Implementation
Map<RK, RV> cast<RK, RV>() => _map.cast<RK, RV>();