We need to create validators for each status. The validator will check if transition from current state is allowed or not. WorkflowExecutionValidator will pick up an appropriate validator from a list and check if transition is allowed. Validators are implemented for each workflow execution status Validators are applied in production code

class WorkflowExecutionValidator {
    List<WorkflowExecutionStatusValidator> validators;
    
    public boolean isTransitionAllowed(WorkflowExecutionStatus currentStatus, WorkflowExecutionStatus newStatus){
        
        //get validator by currentStatus, get a list of validators, check if the new status is in the list of allowed statuses
        
        for(WorkflowExecutionStatusValidator validator: validators){
            if(validator.getCurrentStatus() == currentStatus){
                return validator.isAllowed(newStatus);
            }
        }
        
        return false;
    }
}