### Question:
PGTransactionController extends TransactionController { @Override public boolean canOpenTransaction() { return implictTransactionMarker; } PGTransactionController(); @Override boolean canOpenTransaction(); @Override boolean isAutoCommit(); @Override void setAutoCommit(boolean autoCommit);  }### Answer:
@Test public void testCanOpenTransaction() throws Exception { TransactionController transactionController = new PGTransactionController(); assertFalse(transactionController.canOpenTransaction()); transactionController.setAutoCommit(false); assertFalse(transactionController.canOpenTransaction()); transactionController.markImplicitTransaction(); assertTrue(transactionController.canOpenTransaction()); transactionController.onTransactionEnd(); assertFalse(transactionController.canOpenTransaction()); }