single method

(Entity, A, B, C, D) single()

Implementation

(Entity, A, B, C, D) single() {
  final match = singleOrNull();
  if (match == null) {
    throw StateError(
      'Query4<$A, $B, $C, $D>.single: expected exactly one matching entity, '
      'found none.',
    );
  }
  return match;
}