beginTransaction method
Begins a new transaction
Implementation
StompTransaction beginTransaction(String id) {
if (_transactions.containsKey(id)) {
throw StompTransactionException('Transaction with ID already exists', id);
}
if (_transactions.length >= StompConstants.maxTransactions) {
throw StompTransactionException('Maximum number of transactions reached', id);
}
final transaction = StompTransaction(id: id);
_transactions[id] = transaction;
_beginController.add(transaction);
return transaction;
}