code: public function commit(): bool
  	{
  		if (!$this->isInTransaction) 
  			throw new NotInTransactionException();
  		
  		$this->isInTransaction = false;
  		return $this->executeDirect('COMMIT');
  	}
docs: Commit current transaction.
  @see https://dev.mysql.com/doc/refman/5.7/en/commit.html
  @return bool