* <ul>
* <li>if exception is {@link TransactionCommitFailedException} or one of its subclasses returns original exception.
* <li>if exception is {@link ExecutionException} and cause is {@link TransactionCommitFailedException} return cause
* <ul>
* <li>if exception is {@link TransactionCommitFailedException} or one of its subclasses returns original exception.
* <li>if exception is {@link ExecutionException} and cause is {@link TransactionCommitFailedException} return cause