How to use the domdiv.draw.CardPlot.tabNumber function in domdiv

def nextTab(self, tab=None):
        # For a given tab, calculate the next tab in the sequence
        tab = tab if tab is not None else self.tabIndex
        if CardPlot.tabNumber == 1:
            return 1  # it is the same, nothing else to do

        # Increment if in range
        if 1 <= tab <= CardPlot.tabNumber:
            tab += CardPlot.tabIncrement

        # Now check for wrap around
        if tab > CardPlot.tabNumber:
            tab = 1
        elif tab < 1:
            tab = CardPlot.tabNumber

        if CardPlot.tabSerpentine and CardPlot.tabNumber > 2:
            if (tab == 1) or (tab == CardPlot.tabNumber):
                # reverse direction for next tab
                CardPlot.tabIncrement *= -1
        return tab

def tabSetup(tabNumber=None, cardWidth=None, cardHeight=None, tabWidth=None, tabHeight=None,
                 lineType=None, start=None, serpentine=None, wrapper=None):
        # Set up the basic tab information used in calculations when a new CardPlot object is created.
        # This needs to be called at least once before the first CardPlot object is created and then it
        # needs to be called any time one of the above parameters needs to change.
        CardPlot.tabNumber = tabNumber if tabNumber is not None else CardPlot.tabNumber
        CardPlot.cardWidth = cardWidth if cardWidth is not None else CardPlot.cardWidth
        CardPlot.cardHeight = cardHeight if cardHeight is not None else CardPlot.cardHeight
        CardPlot.tabWidth = tabWidth if tabWidth is not None else CardPlot.tabWidth
        CardPlot.tabHeight = tabHeight if tabHeight is not None else CardPlot.tabHeight
        CardPlot.lineType = lineType if lineType is not None else CardPlot.lineType
        CardPlot.tabStartSide = start if start is not None else CardPlot.tabStartSide
        CardPlot.tabSerpentine = serpentine if serpentine is not None else CardPlot.tabSerpentine
        CardPlot.wrapper = wrapper if wrapper is not None else CardPlot.wrapper
        # LEFT        tabs        RIGHT
        # +---+ +---+ +---+ +---+ +---+
        # | 1 | | 2 | | 3 | |...| | N |   Note: tabNumber = N, N >=1, 0 is for centred tabs
        # +   +-+   +-+   +-+   +-+   +

        # Setup first tab as well as starting point and direction of increment for tabs.
        if CardPlot.tabStartSide == CardPlot.RIGHT:
            CardPlot.tabStart = CardPlot.tabNumber

def nextTab(self, tab=None):
        # For a given tab, calculate the next tab in the sequence
        tab = tab if tab is not None else self.tabIndex
        if CardPlot.tabNumber == 1:
            return 1  # it is the same, nothing else to do

        # Increment if in range
        if 1 <= tab <= CardPlot.tabNumber:
            tab += CardPlot.tabIncrement

        # Now check for wrap around
        if tab > CardPlot.tabNumber:
            tab = 1
        elif tab < 1:
            tab = CardPlot.tabNumber

        if CardPlot.tabSerpentine and CardPlot.tabNumber > 2:
            if (tab == 1) or (tab == CardPlot.tabNumber):
                # reverse direction for next tab
                CardPlot.tabIncrement *= -1

# For a given tab, calculate the next tab in the sequence
        tab = tab if tab is not None else self.tabIndex
        if CardPlot.tabNumber == 1:
            return 1  # it is the same, nothing else to do

        # Increment if in range
        if 1 <= tab <= CardPlot.tabNumber:
            tab += CardPlot.tabIncrement

        # Now check for wrap around
        if tab > CardPlot.tabNumber:
            tab = 1
        elif tab < 1:
            tab = CardPlot.tabNumber

        if CardPlot.tabSerpentine and CardPlot.tabNumber > 2:
            if (tab == 1) or (tab == CardPlot.tabNumber):
                # reverse direction for next tab
                CardPlot.tabIncrement *= -1
        return tab