public function save(ezcWorkflow $workflow)
    {
		// verify workflow
		$workflow->verify();
		
		// calc new version number
		$workflowVersion = $this->getCurrentVersionNumber($workflow->getName()) + 1;
		
		try {
    		$this->_conn->beginTransaction();
		
    		// Mark version that is currenlty the lastest version as old.
    		if ($workflowVersion > 1) {
    			$sql = "WHERE workflow_name = '%s' AND workflow_version_is_latest = %s";
    			$workflowData = 
    				Axiom_Model::getModel('Workflow')->findByQuery(sprintf($sql, $workflow->getName(), 1));
    			$workflowData->workflow_version_is_latest = 0;
    			$workflowData->save();
    		}
		
    		// Write workflow table row
    		$newWorkflowData = new Workflow();
    		$newWorkflowData->workflow_name = $workflow->getName();
    		$newWorkflowData->workflow_version = $workflowVersion;
    		$newWorkflowData->workflow_created = date('Y-m-d H:i:s', time());
    		$newWorkflowData->workflow_version_is_latest = 1;
    		$newWorkflowData->save();
    		
    		$workflow->setId($newWorkflowData->id);
    		$workflow->setVersion($workflowVersion);
		
    		// Write node table rows.
    		foreach ($workflow->getNodes() as $node) {
    			$nodeData = new Node();
    			$nodeClass = get_class($node);
    			$nodeConfiguration = $this->serialize($node->getConfiguration());
			
                // $nodeData->id = $workflow->getId();
    			$nodeData->node_class = $nodeClass;
    			$nodeData->node_configuration = $nodeConfiguration;
    			$nodeData->workflow_id = $newWorkflowData->id;
    			$nodeData->save();
			
    			$node->setId($nodeData->node_id);
    		}
		
    		// Connect node table rows.
    		foreach ($workflow->getNodes() as $node) {
    			foreach ($node->getOutNodes() as $outNode) {
    				$nodeConnData = new NodeConnection();
    				$nodeConnData->incoming_node_id = $node->getId();
    				$nodeConnData->outgoing_node_id = $outNode->getId();
    				$nodeConnData->save();
    			}
    		}
		
    		// Write variable handler row
    		foreach ($workflow->getVariableHandlers() as $variable => $class) {
    			$varHandlerData = new VariableHandler();
    			$varHandlerData->id = $workflow->getId();
    			$varHandlerData->variable = $variable;
    			$varHandlerData->class = $class;
    			$varHandlerData->save();
    		}
		
    		$this->_conn->commit();    
		} catch (Doctrine_Exception $e) {
		    $conn->rollback();
		    throw new Axiom_Workflow_Exception(
				'Could not load definition from db.'
			);
		}
    }