mapTo<T> method
Returns a new lazy Iterable with elements that are created by
calling mapper on each entry of this IMap in
iteration order.
The returned iterable is lazy, so it won't iterate the elements of
this map until it is itself iterated, and then it will apply
mapper to create one element at a time.
The converted elements are not cached.
Iterating multiple times over the returned Iterable
will invoke the supplied mapper function once per element
for on each iteration.
Note: While map returns a new IMap, mapTo returns an Iterable
of elements created by combining the entries keys and values.
Implementation
Iterable<T> mapTo<T>(T Function(K key, V value) mapper) =>
entries.map((MapEntry<K, V> entry) => mapper(entry.key, entry.value));