unzip method
Returns a Pair of iterables, where first Iterable
is built from the
first values of each Pair from this collection, second Iterable
is
built from the second values of each Pair from this collection.
Implementation
Pair<Iterable<E1>, Iterable<E2>> unzip() => Pair(
map((element) => element.first),
map((element) => element.second),
);