Map<K, V>.of constructor

Map<K, V>.of(Map<K, V> other)

Creates a LinkedHashMap with the same keys and values as other.

A LinkedHashMap requires the keys to implement compatible operator== and hashCode, and it allows null as a key. It iterates in key insertion order.

Implementation 

factory Map.of(Map<K, V> other) = LinkedHashMap<K, V>.of;