operator [] method

V operator [] (Object key)
override

Returns the value for the given key or null if key is not in the map.

Some maps allow keys to have null as a value. For those maps, a lookup using this operator cannot distinguish between a key not being in the map and the key having a null value. Methods like containsKey or putIfAbsent can be used if the distinction is important.

Implementation 

V operator [](Object key) => _base[key];