Describes behaviors for both the model status attribute, and the actual status
stored in the SWActiveRecordBehavior.

Definition
	attrib : is the Model status Attribute
	sw     : is the SimpleWorkflow behavior internal SWNode

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Scenario 1 : enter in workflow (auto insertion)
	initial state :
		attrib 		= null
		sw 			= null
		autoinsert 	= true
		
	call swNextStatus() 
		if the default workflow and its initial node can be found insert 
		into workflow, otherwise ERROR
		onSuccess
			attrib <- W/initStatus
			sw <- W/initStatus 
	
	beforeSave() 
		call swNextStatus()

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Scenario 2 : no auto insertion into workflow
	initial state :
		attrib 		= null
		sw 			= null
		autoinsert 	= false

	call swNextStatus() 
		if the default workflow and its initial node can be found insert into 
		workflow, otherwise ERROR
		: attrib <- W/initStatus
		: sw <- W/initStatus 
	
	beforeSave() 
		NOP (because autoinsert = false)
		
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Scenario 3 : enter in workflow
	initial state :
		attrib 		= W/S (set manually)
		sw 			= null

	call swNextStatus() 
		if W/S is an initial status SUCCESS, otherwise ERROR
		: sw <- W/S
		
	beforeSave() 
		call swNextStatus()
		
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Scenario 4 : leave workflow
	initial state :
		attrib 		= null
		sw 			= W/S

	call swNextStatus() 
		if W/S is a final status, otherwise ERROR
		: sw <- null

	beforeSave() 
		call swNextStatus()		
		
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Scenario 5 : transition
	initial state :
		attrib 		= W1/S1
		sw 			= W2/S2

	call swNextStatus() 
		if transition W2/S2 -> W1/S1 exist, perform transition 
		otherwise ERROR
		: attrib <- W2/S2
		
	beforeSave() 
		call swNextStatus()		
		
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Scenario 6 : transition (loop)
	initial state :
		attrib 		= W1/S1
		sw 			= W1/S1

	call swNextStatus() 
		if transition W1/S1 -> W1/S1 exist, perform transition 
		(otherwise no error)
		
	beforeSave() 
		call swNextStatus()