class PlanNode:
    def __init__(self, numNo, strSerialNumber, strModel, numModelNumber, 
                 dateStart, numAssemblyOrder, dateEnd, strOrderOrigin):
        self.numNo = numNo
        self.strSerialNumber = strSerialNumber
        self.strModel = strModel
        self.numModelNumber = numModelNumber
        self.dateStart = dateStart
        self.numAssemblyOrder = numAssemblyOrder
        self.dateEnd = dateEnd
        self.strOrderOrigin = strOrderOrigin

    def printOut(self):
        print('No :', self.numNo, ', SerialNum : ', self.strSerialNumber, 
              ',Model:', self.strModel, ',Start Date:',
              self.dateStart)
    
    def getNextNode(self):
        # Problem 1. complete this method
        node = self.nextNode
        return node

    def getPrevNode(self):
        # Problem 1. complete this method
        node = self.prevNode
        return node
        
    def setNextNode(self, node):
        # Problem 1. complete this method
        self.nextNode = node

    def setPrevNode(self, node):
        # Problem 1. complete this method
        self.prevNode = node
class PlanNode:
    def __init__(self, numNo, strSerialNumber, strModel, numModelNumber, 
                 dateStart, numAssemblyOrder, dateEnd, strOrderOrigin):
        self.numNo = numNo
        self.strSerialNumber = strSerialNumber
        self.strModel = strModel
        self.numModelNumber = numModelNumber
        self.dateStart = dateStart
        self.numAssemblyOrder = numAssemblyOrder
        self.dateEnd = dateEnd
        self.strOrderOrigin = strOrderOrigin

    def printOut(self):
        print('No :', self.numNo, ', SerialNum : ', self.strSerialNumber, 
              ',Model:', self.strModel, ',Start Date:',
              self.dateStart)
    
    def getNextNode(self):
        # Problem 1. complete this method
        node = self.nextNode
        return node

    def getPrevNode(self):
        # Problem 1. complete this method
        node = self.prevNode
        return node
        
    def setNextNode(self, node):
        # Problem 1. complete this method
        self.nextNode = node

    def setPrevNode(self, node):
        # Problem 1. complete this method
        self.prevNode = node
# Problem 1. complete this method # Problem 1. complete this method # Problem 1. complete this method # Problem 1. complete this method