SunnyObservableMap<K, V>.of constructor
Implementation
SunnyObservableMap.of(Map<K, V> map, {String? debugLabel, DiffEquality? diffDelegator})
: _diffEquality = diffDelegator ?? DiffEquality(),
debugLabel = debugLabel ?? "ObservableMap<$K, $V>",
super.of(map) {
_initialize();
}