system/Database/MySQLi/Connection.php
protected function _transRollback(): bool
	{
		if ($this->connID->rollback())
		{
			$this->connID->autocommit(true);

			return true;
		}

		return false;
	}
protected function _transRollback(): bool
	{
		if ($this->connID->rollback())
		{
			$this->connID->autocommit(true);

			return true;
		}

		return false;
	}
Rollback Transaction

@return boolean