transactionStores method Null safety

Transaction transactionStores (
  1. DomStringList storeNames,
  2. String mode
)

Implementation

Transaction transactionStores(DomStringList storeNames, String mode) {
  if (mode != 'readonly' && mode != 'readwrite') {
    throw new ArgumentError(mode);
  }
  return _transaction(storeNames, mode);
}