LinkedHashMap< K, V>.fromEntries constructor
    Creates a LinkedHashMap containing the entries of entries.
Returns a new LinkedHashMap<K, V> where all entries of entries
have been added in iteration order.
If multiple entries have the same key,
later occurrences overwrite the earlier ones.
Implementation
factory LinkedHashMap.fromEntries(Iterable<MapEntry<K, V>> entries) =>
    <K, V>{}..addEntries(entries);