Creates an unmodifiable hash based map containing the entries of
The keys must all be assignable to
K and the values to
other map itself can have any type.
The map requires the keys to implement compatible
hashCode, and it allows
null as a key.
The created map iterates keys in a fixed order,
preserving the order provided by
The resulting map behaves like the result of
except that the map returned by this constructor is not modifiable.
external factory Map.unmodifiable(Map other);