flatten method
Flattens this iterable of iterables into a single iterable.
Flattens each iterable element contained in this iterable into a single iterable. The resulting iterable will contain all the elements if each inner iterable in a single iterable, maintaining iteration order.
(This is a convenience method that is equivalent to calling iterable.expand((e) => e))
.)
Implementation
Iterable<T> flatten() {
return expand((e) => e);
}