shallowCopyMap<K, V> function
Returns a new map with the same entries as source. Keys and values are
shared by reference (not deep-copied).
Example:
shallowCopyMap({'a': 1}); // a new {'a': 1}
Implementation
Map<K, V> shallowCopyMap<K, V>(Map<K, V> source) => Map<K, V>.of(source);