dart:collection

single property

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.

Implementation

E get single {
  if (isEmpty) {
    throw StateError('No such element');
  }
  if (_length > 1) {
    throw StateError('Too many elements');
  }
  return _first!;
}