single property

E get single
override

Checks that this iterable has only one element, and returns that element.

Throws a StateError if this is empty or has more than one element. This operation will not iterate past the second element.

Implementation

E get single {
  if (_count == 1) return _root!.key;
  throw _count == 0
      ? IterableElementError.noElement()
      : IterableElementError.tooMany();
}